United States

This article is about the country in North America. For other uses of terms that redirect here, see US (disambiguation), USA (disambiguation) and United States (disambiguation).

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The United States of America, also known as the United States, the U.S., the U.S.A., and America, is a country in North America. A federal republic, the United States shares land borders with Canada and Mexico, and extends from the Atlantic Ocean to the Pacific Ocean.The United States is also in extremely close proximity to Russia via the state of Alaska; separated only by the Bering Strait. Its capital is Washington, D.C.

The present-day continental United States has been inhabited for at least 15,000 years by indigenous tribes.^[1] After European exploration and settlement in the 16th century, the English established their own colonies, and gained control of others that had been begun by other European nations, in the eastern portion of the continent in the 17th and early 18th centuries. On 4 July 1776, at war with Britain over fair governance, thirteen of these colonies declared their independence; in 1783, the war ended in British acceptance of the new nation. Since then, the country has more than quadrupled in size: it now consists of 50 states and one federal district, and has a number of overseas territories.

At over 3.7 million square miles (over 9.5 million km²), the U.S. is the third or fourth largest country by total area, depending on whether or not the disputed areas of China are included. It is also the world's third most populous nation, with nearly 300 million people.

The United States has maintained a liberal democratic political system since it adopted its Articles of Confederation on 1 March 1781 and the Constitution, the Articles' replacement, on 17 September 1787. American military, economic, cultural, and political influence increased throughout the 20th century; with the collapse of the Soviet Union at the end of the Cold War, the nation emerged as the world's sole remaining superpower.^[2] Today it plays a major role in world affairs.

Contents 1 Name 2 History 3 Government and politics 3.1 Foreign relations and military 4 Administrative divisions 5 Ecology 5.1 Geography and climate 5.2 Flora and fauna 6 Economy 7 Demographics 7.1 Largest cities 7.2 Indigenous peoples 7.3 Language 7.4 Religion 7.5 Education 7.6 Health 8 Culture 9 See also 10 Notes 11 Further reading 12 External links 12.1 Government 12.2 Overviews 12.3 History 12.4 Maps 12.5 Immigration 12.6 Other

Name

See also: List of meanings of countries' names

The earliest known use of the name America is from 1507, when a globe and a large map created by the German cartographer Martin Waldseemüller in Saint-Die-des-Vosges described the combined continents of North and South America. Although the origin of the name is uncertain^[3], the most widely held belief is that expressed in an accompanying book, Cosmographiae Introductio, which explains it as a feminized version of the Latin name of Italian explorer Amerigo Vespucci (Americus Vespucius); in Latin, the other continents' names were all feminine. Vespucci theorized, correctly, that Christopher Columbus, on reaching islands in the Caribbean Sea in 1492, had come not to India but to a "New World".

The Americas were also known as Columbia, after Columbus, prompting the name District of Columbia for the land set aside as the U.S. capital. Columbia remained a popular name for the United States until the early twentieth century, when it fell into relative disuse; but it is still used poetically and appears in various names and titles. A female personification of the country is also called Columbia; she is similar to Britannia.^[4][5][6][7] Columbus Day, a holiday in the U.S. and other countries in the Americas, commemorates Columbus's October 1492 landing.

The term "united States of America" was first used officially in the Declaration of Independence, adopted on 4 July 1776. On 15 November 1777, the Second Continental Congress adopted the Articles of Confederation, the first of which stated "The Stile of this Confederacy shall be 'The United States of America.'"

The adjectival and demonymic forms for the United States are American, a point of controversy among some.

History

Main article: History of the United States

Before the European colonization of the Americas, a process that began at the end of the 15th century, the present-day continental U.S. was inhabited exclusively by various indigenous tribes, including Alaskan natives, who migrated to the continent over a period that may have begun 35,000 years ago and may have ended as recently as 11,000 years ago.^[8] The first confirmed European landing in the present-day United States was by a Spaniard, Juan Ponce de Leon, who landed in 1513 in Florida, and as part of his claim, the first European settlement was established by Don Pedro Menendez de Aviles on the site of a Timucuan Indian village in 1565 at St. Augustine, Florida. The French colonized some of the northeastern portions, and the Spanish colonized most of the southern and western United States. The first successful English settlement was at Jamestown, Virginia, in 1607, followed in 1620 by the Pilgrims' landing at Plymouth, Massachusetts, and then the arrival of the colony of Massachusetts Bay, started by the Puritans. In 1609 and 1617, respectively, the Dutch settled in part of what became New York and New Jersey. In 1638, the Swedes founded New Sweden, in part of what became Delaware, New Jersey, and Pennsylvania after passing through Dutch hands. Throughout the 17th and early 18th centuries, England (and later Great Britain) established new colonies, took over Dutch colonies, and split others. With the division of the Carolinas, in 1729, and the colonization of Georgia, in 1732, the British colonies in North America, excluding present-day Canada, numbered thirteen. These thirteen colonies would be drawn closer together over the coming decades.

Tensions between American colonials and the British during the revolutionary period of the 1760s and 1770s led to open military conflict in 1775. It should be noted that the British Colonies of East and West Florida, and Quebec added by Treaty in 1763 did not join in the rebellion against Great Britain. George Washington commanded the Continental Army during the American Revolutionary War (1775–1783) as the Second Continental Congress adopted the Declaration of Independence on 4 July 1776. The Second Continental Congress had been formed to confront British actions, and did create the Continental Army, but did not have the authority to levy taxes or make federal laws. In 1777, the Congress adopted the Articles of Confederation, uniting the states under a weak federal government, which operated from 1781 until 1788, when enough states had ratified the United States Constitution. The Constitution, which strengthened the union and the federal government, has since remained the supreme law of the land.^[9]

From 1803 to 1848, the size of the new nation nearly tripled as settlers (many embracing the concept of Manifest Destiny as an inevitable consequence of American exceptionalism) pushed beyond national boundaries even before the Louisiana Purchase.^[10] The expansion was tempered somewhat by the stalemate in the War of 1812, but was subsequently reinvigorated by victory in the Mexican–American War in 1848.

As new territories were being incorporated, the nation was divided over the issue of states' rights, the role of the federal government, and, by the 1820s, the expansion of slavery, which had been legal in all thirteen of the colonies but was rarer in the north, where it was abolished by 1804. The Northern states were opposed to the expansion of slavery whereas the Southern states saw the opposition as an attack on their way of life, since their economy was dependent on slave labor. The failure to permanently resolve these issues led to the Civil War, following the secession of many slave states in the South to form the Confederate States of America after the 1860 election of Abraham Lincoln.^[11] The 1865 Union victory in the Civil War effectively ended slavery and settled the question of whether a state had the right to secede. The event was a major turning point in American history, with an increase in federal power.^[12]

After the Civil War, an unprecedented influx of immigrants, who helped to provide labor for American industry and create diverse communities in undeveloped areas, together with high tariff protections, national infrastructure building, and national banking regulations, hastened the country's rise to international power. The growing power of the United States enabled it to acquire new territories, including the annexation of Puerto Rico after victory in the Spanish–American War^[13], which marked the debut of the United States as a major world power.

At the start of the First World War, in 1914, the United States remained neutral. In 1917, however, the United States joined the Allied Powers, helping to turn the tide against the Central Powers. For historical reasons, American sympathies were very much in favor of the British and French, even though a sizable number of citizens, mostly Irish and German, were opposed to intervention.^[14] After the war, the Senate did not ratify the Treaty of Versailles, because of a fear that it would pull the United States into European affairs. Instead, the country pursued a policy of unilateralism that bordered at times on isolationism.^[15]

During most of the 1920s, the United States enjoyed a period of unbalanced prosperity as farm prices fell and industrial profits grew. A rise in debt and an inflated stock market culminated in a crash in 1929, triggering the Great Depression. After his election as President in 1932, Franklin Delano Roosevelt instituted his plan for a New Deal, which increased government intervention in the economy in response to the Great Depression.

The nation did not fully recover until 1941, when the United States was driven to join the Allies against the Axis Powers after a surprise attack on Pearl Harbor by Japan. World War II was the costliest war in American history, but helped to pull the economy out of depression as the required production of military materiel provided much-needed jobs, and women entered the workforce in large numbers for the first time. During this war, scientists working for the United States federal government succeeded in producing nuclear weapons, making the United States the world's first nuclear power. Toward the end of World War II, after the end of World War II in Europe, the United States dropped atomic bombs on Hiroshima and Nagasaki, Japan. Japan surrendered soon after, on September 2, 1945, which ended World War II. ^[16]

After World War II, the United States and the Soviet Union became superpowers in an era of ideological rivalry dubbed the Cold War. The United States promoted liberal democracy and capitalism, while the Soviet Union communism and a centrally planned economy. The result was a series of proxy wars, including the Korean War, the Vietnam War, the tense nuclear showdown of the Cuban Missile Crisis, and the Soviet war in Afghanistan.

The perception that the United States was losing the space race spurred government efforts to raise proficiency in mathematics and science in schools^[17] and led to President Kennedy's call for the United States to land "a man on the moon" by the end of the 1960s, which was realized in 1969.^[18]

Meanwhile, American society experienced a period of sustained economic expansion. At the same time, discrimination across the United States, especially in the South, was increasingly challenged by a growing civil-rights movement headed by prominent African Americans such as Martin Luther King, Jr., which led to the abolition of the Jim Crow laws in the South.^[19]

After the fall of the Soviet Union in 1991, the United States continued to intervene militarily overseas, for example in the Gulf War.

Following the September 11, 2001 attacks, U.S. foreign policy focused on the threat of terrorist attacks. In response, the government under George W. Bush began a series of military and legal operations termed the War on Terror, beginning with the overthrow of Afghanistan's Taliban government in October 2001. Soon after, the United States launched the controversial 2003 invasion of Iraq, with support from 30 governments, which George W. Bush referred to as the 'Coalition of the Willing'. Although the Bush administration justified its invasion with a charge that Iraq had stockpiled weapons of mass destruction, no such stockpile was found and the Bush administration later admitted having acted on flawed intelligence, but as of September 2006 the Iraq war remains an ongoing and controversial event.

Government and politics

Main articles on politics and government of the United States can be found at the Politics and government of the United States series.

The United States is the longest-surviving extant constitutional republic, with the oldest wholly written constitution in the world. Its government operates as a representative democracy through a congressional system under a set of powers specified by its Constitution. There are three levels of government: federal, state, and local. Officials at all three levels are either elected by voters in a secret ballot or appointed by other elected officials. Executive and legislative offices are decided by a plurality vote of citizens in their respective districts, with judicial and cabinet-level offices nominated by the Executive and approved by the Legislature. In some states, judicial posts are filled by popular election rather than executive appointment.

The federal government comprises three branches, which are designed to check and balance one another's powers:

• Legislative: The Congress, made up of the Senate and the House of Representatives.
• Executive: The President, who appoints, with Senate approval, the Cabinet and other officers to help administer federal law.
• Judiciary: The Supreme Court and lower federal courts, whose judges are appointed by the President with Senate approval.

The United States Congress is a bicameral legislature. The House of Representatives has 435 members, each representing a congressional district for a two-year term. House seats are apportioned among the states according to population every tenth year. Each state is guaranteed at least one representative: currently, seven states have one each; California, the most populous state, has 53. Each state has exactly two senators, elected at large to six-year terms; one third of the 100 senators are elected every second year.

Under the country's federal system, the relationship between the state and national governments is complex; under U.S. law, states are considered sovereign entities. However, the American Civil War and Texas v. White established that states do not have the right to secede, and, under the Constitution, they are not allowed to conduct foreign policy. Federal law overrides state law in the areas in which the federal government is empowered to act; but the powers of the federal government are subject to limits outlined in the Constitution. All powers not granted to the federal government in the Constitution are left to the states or the people themselves. However, the "Necessary and Proper" and "Commerce" clauses of the Constitution legally allow the extension of federal powers into other affairs, though this is the topic of considerable debate over states' rights.

The Constitution contains a dedication to "preserve liberty" with a "Bill of Rights" and other amendments, which guarantee freedom of speech, religion, and the press; the right to a fair trial; the right to keep and bear arms; universal suffrage; and property rights. However, the extent to which these rights are protected and universal in practice is heavily debated. The Constitution also guarantees to every State "a Republican Form of Government". However, the meaning of that guarantee has been only slightly explicated.^[20]

There are two major political parties: the Republican Party and the Democratic Party. The Republicans are generally socially conservative and economically classical-liberals with some right-leaning centrists. The Democrats are generally socially liberal and economically progressive with some left-leaning centrists. Growing numbers of Americans identify with neither party—with some claiming the title Independent and others joining emerging parties, including the Green, Libertarian, and Reform parties. Except for a Democratic plurality in the Senate in 2001–2002^[21], the Republican Party has held the majority in both houses of Congress since the 1994 elections; since 2001, the president has been George W. Bush, a Republican.

Foreign relations and military

Main articles: Foreign relations of the United States and Military of the United States

The United States has vast economic, political, and military influence on a global scale, which makes its foreign policy a subject of great interest and discussion around the world. Almost all countries have embassies in Washington, D.C., and consulates around the country. However, Cuba, Iran, North Korea, and Sudan do not have formal diplomatic relations with the United States.^[22] The United States is a founding member of the United Nations (with a permanent seat on the Security Council), among many other international organizations.

In 1949, in an effort to contain communism during the Cold War, the United States, Canada, and ten Western European nations formed the North Atlantic Treaty Organisation, a mutual-defense alliance in which they have since been joined by 14 other European states—including Turkey, which straddles the Eurasian border, and some former Soviet states. In an example of realpolitik, the United States also established diplomatic relations with Communist countries that were antagonistic to the Soviet Union, like the People's Republic of China during the Sino-Soviet split. Recently, the foreign policy of the United States has focused on combating terrorism as well as the proliferation of weapons of mass destruction. Other transnational issues include immigration reform and the shipment of illegal drugs into the country.^[23]

The United States has a long-standing tradition of civilian control over military affairs. The Department of Defense administers the U.S. armed forces, which comprise the Army, the Navy, the Marine Corps, and the Air Force. The Coast Guard falls under the jurisdiction of the Department of Homeland Security in peacetime but is placed under the Department of the Navy in times of war.

The military of the United States comprises 1.4 million personnel on active duty^[24], along with several hundred thousand each in the Reserves and the National Guard. Service in the military is voluntary, though conscription may occur in times of war through the Selective Service System. The United States is considered to have the most powerful military in the world, partly because of the size of its defense budget; American defense expenditures in 2005 were estimated to be greater than the next 14 largest national military budgets combined,^[25] even though the U.S. military budget is only about 4% of the country's gross domestic product.^[26][27] The U.S. military maintains over 700 bases and facilities on every continent except Antarctica.^[28]

The American military is committed to having a technological edge over its potential enemies and has an extensive research program to maintain such an edge. Defense-related research over the years yielded such major breakthroughs as space exploration, computers, the Internet, hypertext, nuclear energy, the Global Positioning System, stealth aircraft, "smart" weapons, better bullet-proof vests, microwaves, and more recently ground-based lasers intended to target and destroy inbound cruise missiles. These force multipliers have traditionally borne more materiel expense than personnel expenses. Military technology maintains a close relationship with the civilian economy and has contributed to general technological and economic development of the United States, and often, via technology transfer, other countries as well. Conversely, the military has also benefited from the American civilian infrastructure.

Administrative divisions

Main article: Political divisions of the United States

The conterminous, or contiguous, forty-eight states—all the states but Alaska and Hawaii—are also called the continental United States. Some include Alaska in the "continental" states, because, although it is separated from the "lower forty-eight" by Canada, it is part of the North American mainland. All of these terms commonly include the District of Columbia. Hawaii, the fiftieth state, occupies an archipelago in the Pacific Ocean.

The United States also holds several other territories, districts, and possessions, notably the federal district of the District of Columbia—which contains the nation's capital city, Washington—and several overseas insular areas, the most significant of which are American Samoa, Guam, the Northern Mariana Islands, Puerto Rico, and the United States Virgin Islands. Palmyra Atoll is the United States' only incorporated territory; but it is unorganized and uninhabited. The United States Minor Outlying Islands consist of uninhabited islands and atolls in the Pacific and Caribbean Sea. In addition, since 1898, the United States Navy has leased an extensive naval base at Guantanamo Bay, Cuba.

Former U.S. possessions include the Panama Canal Zone, which was a U.S. territory from 1903 until 1979. Additionally, the Philippine Islands were American territory from 1898 until 1935, when the United States established the Commonwealth of the Philippines as a transition between territorial status and full Philippine independence, which occurred in 1946. Because it was part of the United States at the time of World War II, the Philippines is the only independent nation with a memorial pillar at the National World War II Memorial in Washington, DC.

In addition to the actual states and territories of the United States, there are also nations which are associated states of the U.S. The Federated States of Micronesia (since 1986), Palau (since 1994), and the Marshall Islands (since 1986) are associated with the United States under what is known as the Compact of Free Association, giving the states international sovereignty and ultimate control over their territory. However, the governments of those areas have agreed to allow the United States to provide defense and financial assistance. The U.S. also treats these nations uniquely by giving them access to many U.S. domestic programs, including disaster response and recovery and hazard mitigation programs under FEMA. The freely associated states are all dependent on U.S. financial assistance to meet both government operational and capital needs. The Office of Insular Affairs administers this financial assistance. The freely associated states also actively participate in all Office of Insular Affairs technical assistance activities. Together with the Commonwealth of the Northern Mariana Islands, each of these associated states were once part of the U.S.-administered UN Trust Territory of the Pacific Islands, which existed from 1947 until 1986 in the case of the Marshall Islands, the Northern Marianas, and the Federated States of Micronesia; Palau's trusteeship ended in 1994.

Ecology

Geography and climate

Main article: Geography of the United States

The United States is the world's third largest country by land area, after Russia and Canada.^[30]. It is bounded by the North Atlantic Ocean to the east, the North Pacific Ocean to the west, Mexico and the Gulf of Mexico to the south, and Canada to the north. Alaska also borders Canada, with the Pacific Ocean to its south and the Arctic Ocean to its north. The state of Hawaii occupies an archipelago in the Pacific Ocean, southwest of the North American mainland.

The U.S. has an extremely varied geography, particularly in the West. The eastern seaboard has a coastal plain which is widest in the south and narrows in the north. The coastal plain does not exist north of New Jersey, although there are glacial outwash plains on Long Island, Martha's Vineyard, and Nantucket. In the extreme southeast Florida is home to the ecologically unique Everglades. Beyond the coastal plain, the rolling hills of the piedmont region end at the Appalachian Mountains which rise above 6,000 feet (1,830 m) in North Carolina and New Hampshire. From the west slope of the Appalachians, the Interior Plains of the Midwest are relatively flat and are the location of the Great Lakes as well as the Mississippi-Missouri River, the world's fourth-longest river system.^[31] West of the Mississippi River, the Interior Plains slope uphill and blend into the vast and often featureless Great Plains. The abrupt rise of the Rocky Mountains, at the western edge of the Great Plains, extends north to south across the continental U.S., reaching altitudes over 14,000 feet (4,270 m) in Colorado.^[32] In the past, the Rocky Mountains had a higher level of volcanic activity; nowadays, the range only has one area of volcanism (the supervolcano underlying Yellowstone National Park in Wyoming, possibly the world's largest volcano), although rift volcanism has occurred relatively recently near the Rockies' southern margin in New Mexico.^[33] Dozens of high mountain ranges, salt flats such as the Bonneville Salt Flats, and valleys are found in the Great Basin region located west of the Rockies and east of the Sierra Nevada, which also has deep chasms, including the Snake River. At the southwestern end of the Great Basin, Death Valley lies 282 feet (86 m) below sea level, the second lowest dry land on Earth. It is the lowest point in the Western Hemisphere and is situated near the Mojave Desert. North of the Great Basin and east of the Cascades in the Northwest is the Columbia River Plateau, a large igneous province shaped by one of the largest flood basalts ever to appear on Earth. It is marked by dark black rocks. Surrounding the Four Corners region lies the Colorado Plateau, named after the Colorado River, which flows through it. The Plateau is generally high in elevation, has highly eroded sandstone, and is a blood red in some locations with many national parks, such as Arches, Bryce Canyon, Grand Canyon, and Zion. West of the Great Basin, the Sierra Nevada mountain range has Mount Whitney, the highest peak in the coterminous U.S. Along the Pacific coast, the Coast Ranges and the volcanic Cascade Range extend from north to south across the country. The northwestern Pacific coast shares the world's largest temperate rain forest with Canada. Alaska has numerous mountain ranges, including Mount McKinley (Denali), the highest peak in North America. Numerous volcanoes can be found throughout the Alexander and Aleutian Islands extending south and west of the Alaskan mainland. The Hawaiian islands are tropical, volcanic islands extending over 1,500 miles (2,400 km), and consisting of six larger islands and another dozen smaller ones that are inhabited.

The U.S. also has the world's highest quality fluorescent minerals and the most number of minerals found in any one location, in an area called the Franklin Furnace. Rock hunters the world over come to hunt for minerals, walk through actual fluorescent mineral mines, and visit mineral museums in Franklin and Ogdensburg, NJ.

The climate of the U.S. is as varied as its landscape. In northern Alaska, tundra and arctic conditions predominate, and the temperature has fallen as low as minus 80 °F (−62 °C).^[34] On the other end of the spectrum, Death Valley, California once reached 134 °F (56.7 °C); the second-highest temperature ever recorded on Earth.^[35]

On average, the mountains of the western states receive the most snow and are among the snowiest places on Earth. The greatest annual snowfall level is at Mount Rainier, in Washington, at 692 inches (1,757.68 cm); the record there was 1,122 inches (2849.8 cm) in the winter of 1971–1972. Other places with significant snowfall outside the Cascade Range are the Wasatch Mountains, near the Great Salt Lake, and the Sierra Nevada, near Lake Tahoe. In the east, while snowfall does not approach western levels, the region near the Great Lakes and the mountains of the Northeast receive the most. Along the northwestern Pacific coast, rainfall is greater than anywhere else in the continental U.S., with Quinault Ranger in Washington having an average of 137.21 inches.^[36] Hawaii receives even more, with 460 inches measured annually on Mount Waialeale, in Kauai. The Mojave Desert, in the southwest, is home to the driest locale in the U.S.—Yuma Valley, Arizona, with an average of 2.63 inches of precipitation each year.^[37]

In central portions of the U.S., tornadoes are more common than anywhere else on Earth^[38] and touch down most commonly in the spring and summer. Deadly and destructive hurricanes occur almost every year along the Atlantic seaboard and the Gulf of Mexico. The Appalachian region and the Midwest experience the worst floods, though virtually no area in the U.S. is immune to flooding. The Southwest has the worst droughts; one is thought to have lasted over 500 years and to have decimated the Anasazi people.^[39]

Flora and fauna

The U.S. has over 17,000 identified native plant and tree species, including 5,000 just in California (which is home to the tallest, the most massive, and the oldest trees in the world).^[40] With habitats ranging from tropical to arctic, the flora of the U.S. is the most diverse of any country; yet, thousands of non-native exotic species sometimes adversely affect indigenous plant and animal communities. Over 400 species of mammal, 700 species of bird, 500 species of reptile and amphibian, and 90,000 species of insect have been documented.^[41] Many plants and animals are very localized in their distribution, and some are in danger of extinction. The U.S. passed the Endangered Species Act in 1973, to protect native plant and animal species and their habitats.

Conservation has a long history in the U.S.; in 1872, the world's first National Park was established, at Yellowstone. Another 57 national parks and hundreds of other federally managed parks and forests have since been designated.^[42] In some parts of the country, wilderness areas have been established to ensure long-term protection of pristine habitats. The U.S. Fish and Wildlife Service monitors endangered and threatened species and has set aside numerous areas for species- and habitat-preservation. Altogether, the U.S. government owns 1,020,779 square miles (2,643,807 km²) which is 28.8% of the total land area of the U.S.^[43] The bulk of this land is protected park and forestland; but some is leased for oil and gas exploration, mining, and cattle ranching.

Economy

Main articles: Economy of the United States, Science and technology in the United States, Household income in the United States, Transportation in the United States, and American middle class

The economic history of the United States is a story of economic growth that began with marginally successful colonial economies and progressed to the largest industrial economy in the world in the 20th and early 21st century.

The economic system of the United States can be described as a capitalist mixed economy, in which corporations, other private firms, and individuals make most microeconomic decisions, and governments prefer to take a smaller role in the domestic economy, although the combined role of all levels of government is relatively large, at 36% of the GDP. The U.S. has a small social safety net, and regulation of businesses is slightly less than the average of developed countries.^[44] The United States' median household income in 2005 was $43,318.^[45]

Economic activity varies greatly across the country. For example, New York City is the center of the American financial, publishing, broadcasting, and advertising industries, while Los Angeles is the most important center for film and television production. The San Francisco Bay Area and the Pacific Northwest are major centers for technology. The Midwest is known for its reliance on manufacturing and heavy industry, with Detroit serving as the historic center of the American automotive industry, and Chicago serving as the business and financial capital of the region. The Southeast is a major area for agriculture, tourism, and the lumber industry, and, because of wages and costs below the national average, it continues to attract manufacturing.

The largest sector in the United States economy is services, which employs roughly three quarters of the work force.^[46] The economy is fueled by an abundance in natural resources such as coal, petroleum, and precious metals. However, the country still depends for much of its energy on foreign countries. In agriculture, the country is a top producer of corn, soy beans, rice, and wheat, with the Great Plains labeled as the "breadbasket of the world" for their tremendous agricultural output.^[47] The U.S. has a large tourist industry, ranking third in the world^[48], and is also a major exporter in goods such as airplanes, steel, weapons, and electronics. Canada accounts for 19% (more than any other nation) of the United States' foreign trade, followed by China, Mexico, and Japan.

While the per capita income of the United States is among the highest in the world, the wealth is comparatively concentrated, with approximately 40% of the population earning less than an average resident of western Europe and the top 20% earning substantially more.^[49] Since 1975, it has had what can be called a "two-tier" labor market, in which virtually all the real income gains have gone to the top 20% of households.^[50] This polarization is the result of a relatively high level of economic freedom.^[51]

The social mobility of U.S. residents relative to that of other countries is the subject of much debate. Some analysts have found that social mobility in the United States is low relative to other OECD states, specifically compared to Western Europe, Scandinavia and Canada.^{[52] [53] [54]} Low social mobility may stem in part from the U.S. educational system. Public education in the United States is funded mainly by local property taxes supplemented by state revenues. This frequently results in a wide difference in funding between poor districts or poor states and more affluent jurisdictions. ^{[55] [56]} In addition, the practice of legacy preference at elite universities gives preference to the children of alumni, who are often wealthy. This practice reduces available spaces for better-qualified lower income students.^[57] Some analysts argue that relative social mobility in the U.S. peaked in the 1960s and declined rapidly beginning in the 1980s.^[58] Former Federal Reserve Board Chairman Alan Greenspan has also suggested that that the growing income inequality and low class mobility of the U.S. economy may eventually threaten the entire system in the near future. ^[59]

The United States is an influential country in scientific and technological research and the production of innovative technological products. During World War II, the U.S. was the first to develop the atomic bomb, ushering in the atomic age. Beginning early the Cold War, the U.S. achieved successes in space science and technology, leading to a space race, which led to rapid advances in rocketry, weaponry, material science, computers, and many other areas. This technological progress was epitomized by the first visit of a man to the moon, when Neil Armstrong stepped off of Apollo 11 in July 1969.^[60] The U.S. was also perhaps the most instrumental nation in the development of the Internet, through the funding of its predecessor, Arpanet, and the actual physical presence of much of the Internet.

In the sciences, Americans have a large share of Nobel Prizes, especially in the fields of physiology and medicine. The National Institutes of Health, a focal point for biomedical research in the United States, has contributed to the completion of the Human Genome Project.^[61] The main governmental organization for aviation and space research is the National Aeronautics and Space Administration. Major corporations, such as Boeing and Lockheed Martin, also play an important role.

The automobile industry developed earlier and more rapidly in the United States than in most other countries. The backbone of the nation's transportation infrastructure is a network of high-capacity highways. From data taken in 2004, there are about 3,981,521 miles (6,407,637 km) of roadways in the U.S., the most in the world.^[62]

Mass transit systems exist in large cities, such as New York, which operates one of the busiest subway systems in the world. With a few exceptions, American cities are less dense than those in other parts of the world. Low density partly results from and largely necessitates automobile ownership by most households.

Whereas the freight rail network is among the world's best (and most congested), the passenger rail network is underdeveloped by European and Japanese standards. This is partly because of the longer distances traveled in the U.S.; a destination two thousand miles (3,000 km) away is reached more quickly by air than by rail. Government subsidies of air travel played a role in the bankruptcy of passenger-rail corporations in the 1970s. The U.S. had been unique in its high number of private passenger railroads. During the 1970s, government intervention reorganized freight railroads, and consolidated passenger service under the government-backed corporation Amtrak. No other country has more miles of rail than the U.S.^[63]

Air travel is the preferred means of travel for long distances. In terms of passengers, seventeen of the world's thirty busiest airports in 2004 were in the U.S., including the world's busiest, Hartsfield–Jackson Atlanta International Airport (ATL). In terms of cargo, in the same year, twelve of the world's thirty busiest airports were in the U.S., including the world's busiest, Memphis International Airport.

Several major seaports are in the United States; the three busiest are California's Port of Los Angeles and Port of Long Beach, and the Port of New York and New Jersey, all among the world's busiest. The Great Lakes also carry shipping traffic, the lakes being extensively connected to one another, the Mississippi River system, and the Atlantic Ocean. The first water link between the Great Lakes and the Atlantic, the Erie Canal, allowed the rapid expansion of agriculture and industry in the Midwest, and made New York City the economic center of the U.S.

Demographics

Main article: Demographics of the United States

As of August 2006, the United States' population was estimated at 299,059,138, with an annual growth rate of about 0.59%.^[64] This figure includes persons living in the U.S. without legal permission to do so, estimated at 12 million, and excludes U.S. citizens living abroad, estimated at 3 million to 7 million. The United States Census Bureau predicts that the population will surpass 300 million in October 2006. In 2000, about 79% of the population lived in urban areas.^[65]

Thirty-five million Americans, about 12.6% of the population, live in poverty. About 15.8% of households have annual incomes of at least $100,000; and the top 10% of households had annual gross incomes exceeding $118,200 in 2003.^[66] Overall, the top quintile, those households earning more than $86,867 a year, earned 49.8% of all income in 2003.^[67]

In the 2000 census, the country had 31 ethnic groups with at least one million members each, with numerous others represented in smaller amounts.^[68] By the federal government's categorization of race, most Americans (80.4% in 2004)^[69] are white. These white Americans are mostly European Americans—the descendants of European immigrants to the United States—along with some non-Europeans counted as white in government nomenclature—that is, those with origins in the original peoples of the Middle East and North Africa. To the exclusion of Hispanic-origin European Americans, non-Hispanic whites constituted 67.4% of the population. The non-Hispanic white population is proportionally declining, because of both immigration by, and a higher birth rate among, ethnic and racial minorities.^[70] If current immigration trends continue, the number of non-Hispanic whites is expected to be reduced to a plurality by 2040-2050. The largest ethnic group of European ancestry is German at 15.2%, followed by Irish (10.8%), English (8.7%), Italian (5.6%) and Scandinavian (3.7%). Many immigrants also hail from Slavic countries, such as Poland and Russia, as well as from French Canada.^[71] African Americans, or Blacks, largely descend from Africans who arrived as slaves during the seventeenth through nineteenth centuries, and number about 35 million or 12.9% of the population. At about 1.5% of the total population, Native Americans and Alaska Natives number about 4.4 million^[72], approximately 35% of whom were living on reservations in 2005^[73].

Current demographic trends include the immigration of Hispanics from Latin America into the Southwest, a region that is home to about 60% of the 35 million Hispanics in the United States. Immigrants from Mexico make up about 66% of the Hispanic community^[74], and are second only to the German-descent population in the single-ethnicity category. The Hispanic population, which has been growing at an annual rate of about 4.46% since the 1990s, is expected to increase significantly in the coming decades, because of both immigration and a higher birth rate among Latinos than among the general population.^[75]

Largest cities

Main article: List of United States cities by population

The United States has dozens of major cities, which play an important role in U.S. culture, heritage, and economy. In 2004, 251 incorporated places had populations of at least 100,000 and nine had populations greater than 1,000,000, including several important global cities, such as New York City, Los Angeles, and Chicago. In addition, there are fifty metropolitan areas with populations over 1,000,000.

Rank	City	Population within city limits	Population Density per sq mi	Metropolitan Area		Region
				millions	rank
1	New York City, New York	8,143,197	26,402.9	18.7	1	Northeast
2	Los Angeles, California	3,844,829	7,876.8	12.9	2	West
3	Chicago, Illinois	2,842,518	12,750.3	9.4	3	Midwest
4	Houston, Texas	2,016,582	3,371.7	5.2	7	South
5	Philadelphia, Pennsylvania	1,463,281	11,233.6	5.8	4	Northeast
6	Phoenix, Arizona	1,461,575	2,782.0	3.7	14	West
7	San Antonio, Texas	1,256,509	2,808.5	1.8	29	South
8	San Diego, California	1,255,540	3,771.9	2.9	17	West
9	Dallas, Texas	1,213,825	3,469.9	5.7	5	South
10	San Jose, California	912,332	5,117.9	1.7	30	West

Indigenous peoples

Main article: Native Americans in the United States

The Native Americans of the United States (also known as Indians or American Indians, among others), are an ethnic group who have populated the land that is today the United States since at least 9,000 B.C., more than one hundred centuries before the arrival of European settlers. As in other countries throughout the Western Hemisphere, the impact of European colonization of the Americas changed the lives and cultures of the Native Americans. In the 15th to 19th century, their populations were ravaged by displacement, disease, warfare with the Europeans, and enslavement.

In the 19th century, the incessant westward expansion of the United States incrementally compelled large numbers of Native Americans to resettle further west, sometimes by force, almost always reluctantly. Under President Andrew Jackson, Congress passed the Indian Removal Act of 1830, which authorized the president to conduct treaties to exchange Native American land east of the Mississippi River for lands west of the river. As many as 100,000 Native Americans eventually relocated in the West as a result of this Indian Removal policy. In theory, relocation was supposed to be voluntary (and many Native Americans did remain in the East), but in practice great pressure was put on Native American leaders to sign removal treaties.

Conflicts, generally known as "Indian Wars", broke out between U.S. forces and many different tribes. U.S. government authorities entered numerous treaties during this period, but later abrogated many for various reasons. On January 31, 1876, the United States government ordered all remaining Native Americans to move into reservations or reserves.

The Indian Citizenship Act of 1924 gave United States citizenship to Native Americans, in part because of an interest by many to see them merged with the American mainstream, and also because of the heroic service of many Native American veterans in the First World War.

As of 2003 according to the 2003 United States Census Bureau estimates, there were 2,786,652 Native Americans in the United States. However, a large number of indigenous peoples from Latin American countries, particularly Mexico, have migrated to the U.S. over the years. Other tribes, such as the Yaqui have persisted on both sides of the U.S./Mexican border crossing freely for many years until the current border clampdown (see illegal immigration).

Language

Main article: Languages in the United States

Although the United States has no official language, English is the de facto national language. In 2003, about 214.8 million, or 81.6%, of the population aged five years and older spoke only English at home.[3] Although not all Americans speak English, it is the most common language for daily interaction among both native and non-native speakers. Knowledge of English is required of immigrants seeking naturalization. Some Americans advocate making English the official language, which it is in twenty-seven individual states. Three states also grant official status to other languages alongside English: French in Louisiana, Hawaiian in Hawaii, and Spanish in New Mexico.^[76] Besides English, languages spoken at home by at least one million Americans aged five years and up are Spanish or Spanish Creole, spoken by 29.7 million; Chinese, 2.2 million; French (including Patois and Cajun), 1.4 million; Tagalog, 1.3 million; Vietnamese, 1.1 million; and German, 1.1 million.^[70][77]

Religion

Main article: Religion in the United States

The United States government keeps no official register of Americans' religious status. However, in a private survey conducted in 2001 and mentioned in the Census Bureau's Statistical Abstract of the United States, 76.7% of American adults identified themselves as Christian; about 52% of adults described themselves as members of various Protestant denominations; Roman Catholics, at 24.5%, were the most populous individual sect; Judaism (1.4%), the Church of Jesus Christ of Latter-day Saints (1.3%), and other faiths also have firm places in American culture; about 14.2% of respondents described themselves as having no religion; the religious distribution of the 5.4% who elected not to describe themselves for the survey is unknown.^[64]

The country has a relatively high level of religiosity among developed nations. About 46% of American adults say that they attend religious services at least once a week, compared with 14% of adults in Great Britain, 8% in France, and 7% in Sweden. Moreover, 58% of Americans say they often think about the meaning and purpose of life, compared with 25% of the British, 26% of the Japanese, and 31% of West Germans.^[78] However, this rate is not uniform across the country: regular attendance to religious services is markedly more common in the Bible Belt, composed largely of Southern and Southern Midwestern states, than in the Northeast or the West.^[79]

Religion among some Americans is highly dynamic: over the period 1990–2001, those groups whose portion of the population at least doubled were, in descending order of growth, Wiccans, nondenominational Christians, Deists, Sikhs, Evangelical Christians, Disciples of Christ, New Age adherents, Hindus, Full Gospel adherents, Quakers, Bahá'ís, independent Christians, those who refused to answer the question, Buddhists, and Foursquare Gospel adherents.^[64]

Over the same period, the group whose portion of the population grew by the most percentage points was those who claimed no religion, making up 8.2% of the adult population in 1990, but 14.2% in 2001.