United States

The United States of America is a country mostly located in North America. Its short names are the United States (U.S.) and America. It is a federal republic made up of 50 states and a federal capital district, Washington, D.C. The 48 contiguous states border Canada to the north and Mexico to the south. The semi-exclave of Alaska lies in the northwest, and the archipelago of Hawaii is in the Pacific Ocean. The United States also claims five major island territories and various uninhabited islands in Oceania and the Caribbean. It is a megadiverse country, with the world's fourth-largest total area and third-largest population, exceeding 341 million. Several terms redirect here. For other uses, see United States (disambiguation), America (disambiguation), US (disambiguation), USA (disambiguation), The United States of America (disambiguation) and The States (disambiguation).

Paleo-Indians migrated from North Asia to North America at least 15,000 years ago and formed various civilizations. Beginning in 1607, British colonization established the Thirteen Colonies. The 18th-century American Enlightenment spread values of republicanism and liberalism there. Clashes with the British Crown over taxation without parliamentary representation, among other denied rights, sparked the American Revolution. Independence from Great Britain was formally declared in the Lee Resolution of July 2, 1776, two days before the Declaration of Independence. Victory in the 1775–1783 Revolutionary War brought international recognition of U.S. sovereignty.

The U.S. expanded westward through the purchase, settlement, and conquest of European- and Indigenous-controlled territory. As more states joined the Union, a sectional division over slavery led 11 Southern states to declare secession and form the Confederate States of America, fighting the Union in the Civil War of 1861–1865. With the United States' victory and reunification, slavery was abolished. By 1900, the U.S. emerged as a great power, a status solidified after its involvement in World War I. Following Japan's attack on Pearl Harbor in 1941, it entered World War II on the Allied side. The war's aftermath left the U.S. and the Soviet Union as rival superpowers, vying for geopolitical dominance during the Cold War. The Soviet Union's collapse in 1991 left the U.S. as the world's sole superpower, although it has faced competition from China in the 2020s.

The U.S. federal government is a republic under the Constitution, which created a separation of powers among legislative, executive, and judicial branches. Executive authority is vested in a president, while Congress is a bicameral national legislature composed of the House of Representatives (a lower house based on population) and the Senate (an upper house based on equal representation for each state). The Supreme Court exercises judicial review, under which it may hold laws or governmental actions unconstitutional. Federalism grants substantial autonomy to the 50 states.

A developed country, the United States ranks high in economic competitiveness, innovation, and higher education. Its economy accounts for over a quarter of nominal global GDP and has been the world's largest since about 1890. The U.S. is the wealthiest country, with the highest disposable household income per capita among OECD members, though its wealth inequality is highly pronounced. American culture, shaped by centuries of immigration, is diverse and globally influential. The U.S. makes up nearly a third of global military spending and is widely considered to have the most powerful armed forces in the world. A member of numerous international organizations, it plays a dominant role in global political, cultural, economic, and military affairs.

Etymology

Further information: Names of the United States, Demonyms for the United States, United Colonies, and Naming of the Americas

The phrase "United States of America" has been recorded since January 2, 1776. On that day, Stephen Moylan, an aide in the Continental Army to General George Washington, wrote to Joseph Reed, Washington's aide-de-camp. He wanted to travel "with full and ample powers from the United States of America to Spain" to seek help for the Revolutionary War. The first known public use was in an anonymous essay printed in the Williamsburg newspaper The Virginia Gazette on April 6, 1776. On or after June 11, 1776, Thomas Jefferson wrote "United States of America" in a rough draft of the Declaration of Independence, which the Second Continental Congress adopted on July 4, 1776.

"United States" and "U.S." are common short names for the country, and "USA" is also widely used. These are the official terms used throughout the U.S. federal government. People outside the country often say "The States," and "stateside" describes things related to it. The word "America" comes from the first name of Americus Vesputius, the Latin form of the name of Italian explorer Amerigo Vespucci (1454–1512). German mapmakers Martin Waldseemüller and Matthias Ringmann first used it as a place name in 1507. Vespucci believed the West Indies that Christopher Columbus found in 1492 were part of a new landmass, not the Indies near Asia. In English, the term "America" rarely refers to anything unrelated to the United States. "The Americas" is the general name for the continents of North and South America.

History

Main article: History of the United States

Main articles: History of Native Americans in the United States and Pre-Columbian era

Main articles: Colonial history of the United States and Colonial American military history

Main articles: History of the United States (1776–1789), History of the United States (1789–1815), American Revolution, and Founding Fathers of the United States

Main articles: History of the United States (1815–1849) and History of the United States (1849–1865)

Main article: History of the United States (1865–1917)

Main article: History of the United States (1917–1945)

Main articles: History of the United States (1945–1964), History of the United States (1964–1980), and History of the United States (1980–1991)

Main articles: History of the United States (1991–2016) and History of the United States (2016–present)

The first inhabitants of North America migrated from Siberia at least 15,000 years ago, and Indigenous cultures later grew more advanced. Some, such as the Mississippian culture, developed agriculture and complex societies. Christopher Columbus began exploring the Caribbean for Spain in 1492, and Spain's first colony in the present-day continental United States, Spanish Florida, was chartered in 1513. British colonization of the East Coast began with the Virginia Colony in 1607 and the Plymouth Colony in 1620. The colonies were governed as possessions of the British Empire, but the British attempt to disarm the colonists led to the 1775 Battles of Lexington and Concord, which started the American Revolutionary War. The Declaration of Independence was adopted on July 4, 1776. After the siege of Yorktown in 1781, American independence was recognized by the Treaty of Paris (1783). The U.S. Constitution went into effect in 1789, and George Washington was elected the country's first president. The Louisiana Purchase of 1803 from France nearly doubled the size of the United States. The Indian Removal Act of 1830 led to the Trail of Tears, in which many Native Americans were forced to move west. Disagreements over slavery grew between the North and South, and in 1860–1861, 11 slave states voted to secede from the United States, which led to the American Civil War (1861–1865). After the war, the Reconstruction Amendments to the Constitution were ratified, and Alaska was purchased from Russia in 1867.

Over the next decades, many immigrants arrived, and the country grew quickly with new railroads and industries. The Spanish–American War led to the United States gaining Puerto Rico and Guam, and Hawaii was annexed in 1898. The United States entered World War I in 1917, and women across the country won the right to vote in 1920. After the Wall Street Crash of 1929 started the Great Depression, President Franklin D. Roosevelt introduced the New Deal. The United States entered World War II in December after Japan's attack on Pearl Harbor. After the war, the United States and the Soviet Union became superpowers in the Cold War, and the United States reached the Moon in 1969 with the first crewed Moon landing. The civil rights movement, led by Martin Luther King Jr., worked to end unfair treatment of African Americans. The Cold War ended as the Soviet Union dissolved between 1989 and 1991. The September 11 attacks in 2001 led the U.S. to launch the war on terror, and the Great Recession followed in 2007. In recent years, the country has seen increased political polarization, including the January 2021 Capitol attack when a mob entered the U.S. Capitol.

Geography

Main article: Geography of the United States

Glacier Point in Yosemite National Park, California

The South Rim of the Grand Canyon, Arizona

Mountains in Denali National Park, Alaska

The United States is the third or fourth largest country by total area. Its land includes the coastal plain of the Atlantic coast, forests and hills in the Piedmont region, and the Appalachian Mountains. The Mississippi River System, one of the world's longest river systems, runs through the middle of the country. Flat, fertile prairie covers the Great Plains, and the Rocky Mountains run north to south farther west. There are deserts in the Southwest and the Grand Canyon, a steep canyon carved by the Colorado River in Arizona. The Cascade and Sierra Nevada mountains run near the Pacific coast. Alaska is separated from the rest of the country, and its Denali is the highest peak in the country and on the continent. Hawaii has six active volcanoes, including Kilauea and Mauna Loa.

Main article: Climate of the United States

See also: Climate change in the United States

The country has many climate types. The climate ranges from humid continental in the north to humid subtropical in the south, and it is tropical in Hawaii and the southern tip of Florida. The United States gets more high-impact extreme weather than any other country, and most of the world's tornadoes happen in the country, mainly in Tornado Alley. Because of climate change, extreme weather has become more common in the 21st century. The country is also home to many plants and animals. It has 63 national parks, and the National Park Service and other agencies manage many other protected places. The U.S. Environmental Protection Agency is the federal agency that handles most environmental issues.

Main articles: Fauna of the United States and Flora of the United States

The Endangered Species Act of 1973 helps protect threatened and endangered species and their habitats, and the United States Fish and Wildlife Service carries out the law.

Government and politics

Main article: Politics of the United States

The United States is a federal republic made up of 50 states and the federal capital district of Washington, D.C. Its government has three branches, all based in Washington, D.C. Congress meets in the Capitol Building, which houses both chambers of Congress. The president lives and works in the White House, and the Supreme Court building houses the nation's highest court. The Constitution is the country's most important legal document. It sets up a separation of powers with checks and balances, so no single branch can become supreme. This presidential system differs from the parliamentary system, and many newly independent countries have adopted parts of it. Congress is a bicameral legislature with a Senate and a House of Representatives. The president is the head of state and leads the executive branch, and a presidential election is an indirect election decided by the Electoral College. The federal judiciary includes the Supreme Court, the U.S. courts of appeals, and the U.S. district courts. Judges can review laws through judicial review.

The U.S. has a two-party system in practice, mainly led by the Democratic Party and the Republican Party. Its government is divided into states, counties, and Indian country, along with territories and local governments. The country also works with other nations through foreign relations and foreign policy, and its armed forces are led by the president as commander-in-chief. The law of the United States is enforced through local police, state courts, and federal agencies such as the Federal Bureau of Investigation.

Further information: List of states and territories of the United States, List of federally recognized tribes by state, and Federally recognized tribe

Further information: List of political parties in the United States and Political party strength in U.S. states

Main articles: Law of the United States, Law enforcement in the United States, and Crime in the United States

Economy

Main article: Economy of the United States

See also: Lists of companies of the United States by state

The U.S. has a highly developed mixed economy that has been the world's largest since about 1890. In 2024, its gross domestic product (GDP) was more than $29 trillion, over 25% of the world's economic output. The country ranks first in the world by nominal GDP. In August 2026, the total U.S. federal government debt passed $40 trillion. In 2025, 138 of the world's 500 largest companies had their headquarters in the U.S., the most of any country. The U.S. dollar is the currency most used in international transactions.

The U.S. is still a major industrial power, and its manufacturing sector was the world's second-largest by value in 2024, after China's. New York City is the world's main financial center. The United States is the world's largest importer and second-largest exporter, and it is the world's largest exporter of services by far. Wealth is highly concentrated, and about 37.9 million people, or 11.5% of the population, were living in poverty in 2022.

Main article: Science and technology in the United States and Science policy of the United States

The United States has been a leader in technological innovation since the late 19th century. It continues to be one of the world's foremost scientific powers. NASA was established in 1958, and in 1961 the United States became the second country to launch a human into space. The Apollo 11 mission achieved the first crewed Moon landing in 1969.

Main article: Energy in the United States

In 2023, about 84% of the U.S. energy came from fossil fuel. The U.S. is the world's largest producer of nuclear power.

Main article: Transportation in the United States

The United States has a road network of about 4 million miles (6.4 million kilometers), the longest in the world. The Interstate Highway System connects all major U.S. cities. Long-distance travel is provided mostly by airlines, and the country has an extensive air transportation network.

Demographics

Main article: Demographics of the United States

The U.S. Census Bureau reported 331,449,281 residents on April 1, 2020, making the United States the third-most-populous country in the world, after India and China. About 82% of Americans live in metropolitan areas, mostly in suburbs. Four cities, New York City, Los Angeles, Chicago, and Houston, have more than two million residents. The country's population is diverse. White Americans are the largest racial and ethnic group at 57.8%, followed by Hispanic and Latino Americans at 18.7% and African Americans at 12.1%. English is by far the most commonly spoken language, and it was designated the official language by Executive Order 14224 in March 2025. Spanish is the second most commonly used language at home. In 2022, there were 87.7 million immigrants and U.S.-born children of immigrants in the country, nearly 27% of the population.

The First Amendment protects the free exercise of religion in the country and stops Congress from passing laws about its establishment. Religious practice is widespread and among the most diverse in the world. The country has the world's largest Christian population. Many Americans follow other faiths, including Judaism, Buddhism, Hinduism, and Islam. Mormonism is the main religion in Utah. Life expectancy at birth reached 79.0 years in 2024, the highest level recorded, according to the Centers for Disease Control and Prevention (CDC). Heart disease, cancer, and unintentional injuries remained the leading causes of death. Public education is organized mainly by state governments, and children generally attend school from age five or six until age 18. The U.S. has produced the most Nobel Prize winners of any country, and many of the world's top universities are in the United States.

Culture and society

Main articles: Culture of the United States and Society of the United States

See also: Human rights in the United States

The United States is home to a wide variety of ethnic groups, traditions, and customs. It has been described as having the values of individualism and personal autonomy, along with a strong work ethic and competitiveness. Giving to others also plays a major role. A 2016 study by the Charities Aid Foundation found that Americans donated 1.44% of total GDP to charity, the highest rate in the world by a large margin. Americans have traditionally been united by an "American Creed" that emphasizes liberty, equality under the law, democracy, and a preference for limited government. Nearly all Americans or their ancestors came from Europe, Africa, or Asia within the past five centuries. Mainstream American culture is a Western culture largely shaped by traditions of European immigrants, with influences from many other sources. Under the First Amendment to the Constitution, the United States is considered to have the strongest protections of free speech of any country. The American Dream, the belief that Americans enjoy high levels of social mobility, helps attract immigrants.

The United States has also gained influence through its cultural exports, including American movies, music, video games, sports, and food. Its mass media include major broadcasters such as the National Broadcasting Company and the Public Broadcasting Service, and newspapers with a global reach, such as The New York Times. American literature has a long history, from early novels to the Harlem Renaissance and the Nobel Prize in Literature, which American laureates have won twelve times. The country is known for its theater, especially Broadway in New York City, and for its visual art and architecture. American music has influenced the world, from jazz and rock and roll to hip hop. American fashion is informal, with New York counted among the major fashion capitals. The film industry centered in Hollywood has a worldwide following. American cuisine combines Native American foods with dishes from immigrant groups. Popular sports include American football, basketball, baseball, and ice hockey, and the United States has hosted the Olympic Games eight times.