United States of America
Usa flag
Usa location
Largest city
Washington, D.C.
New York City
Official language
National language
English (de facto)
Demonym American
- President

- Vice President
- Speaker of the House

- Chief Justice

Barack Obama
Joe Biden
John Boehner

John Roberts
- Upper house
- Lower house
House of Representatives

- Declared
- Recognized

- Constitution

Great Britain
July 4, 1776
September 3, 1783

June 21, 1788
Area 3,800,000 sq. mi.
9,800,000 sq. km.
316,000,000 (3rd)
83 / mi²; 32 / km²
Per capita
15.6 trillion (1st)
HDI Very high
Currency U.S. Dollar
Drives on the
Calling code
Internet TLD
.us, .gov, .mil, .edu

The United States, officially known as the United States of America and commonly referred to as America, is a federal constitutional republic of 50 states located in North America. Its capital is Washington, D.C., and its largest city and economic center is New York.

The United States is the third largest country by area, after Russia and Canada. With a population of 315 million, it is also the third most populous. The nation's geography varies, ranging from temperate forests in the east to the Great Plains in the country's heartland, to a mountainous west. The United States is bordered to the north by Canada and to the south by Mexico

The United States is one of the most diverse nations on Earth, primarily due to immigration. The first wave of immigration in the colonial period brought mostly English political and religious refugees. In the 19th century, large numbers of Irish people and Germans crossed the Atlantic, followed by Italians, Greeks, and Russians in the early 20th century. In the post-war period, the majority of immigrants hail from Latin America or Asia; over 16 percent of the population is Hispanic or Latino.

With a nominal GDP of $15 trillion, the United States economy is the largest in the world. After World War II and into the 21st century, the United States remains the world's dominant economic, political and scientific force. While rapidly industrializing nations in South America, Africa and Asia are countering US influence, the United States remains the largest and most powerful developed nation in the world.


Main article: History of the United States

Pre-independence periodEdit

The United States was occupied by diverse Native American groups prior to European contact. European colonization began in earnest in the first half of the 16th century. By 1750, most of the East Coast had been colonized by Great Britain, while the Southwestern United States were settled by the Spanish. In the 1770s, widespread discontent about British taxes and military presence exploded into full-scale revolt. The American Revolutionary War lasted from 1775 to 1783 and resulted in American independence. A democratic government was established under the Articles of Confederation and later the United States Constitution.

Antebellum eraEdit

The United States expanded greatly in both population and area in the antebellum era. Waves of immigrants, primarily from famine-ravaged Ireland and war-torn Germany, contributed to the massive population growth. The Louisiana Purchase of 1804 more than doubled the land area of the nation, and the Mexican-American War secured control over the Southwest, Texas, and California. Unfortunately, the territorial enlargement of the Union raised tensions between the more industrial North and the more agrarian South. Every time a new state was admitted to the Union, fierce arguments broke out over whether slavery would be permitted. The Missouri Compromise of 1820 attempted to settle the debate by setting a line above which slavery would be forbidden, but it was superseded by the Kansas-Nebraska Act of 1853. Rhetoric became increasingly inflamed on both sides as the North grew more and more in favor of total abolition of slavery.

Civil WarEdit

These tensions exploded into war when Abraham Lincoln, a pro-North Republican, was elected President in 1860. In response, 11 states in the South seceded and formed the Confederate States of America. Unwilling to allow the Union to fall apart, Lincoln authorized military action, starting the American Civil War on April 12, 1861. Despite the North's larger population and resources, the Confederacy initially outmaneuvered the Union with the aid of brilliant generals such as Robert E. Lee and Thomas "Stonewall" Jackson. However, the defeat of Lee at the Battle of Gettysburg in 1863 spelled the beginning of the end of the Confederacy, but not before two more years of wanton bloodshed and the assassination of President Lincoln just weeks before the end of the war. The new President, Andrew Johnson, declared the rebellion over on May 9, 1865.

Reconstruction and the Progressive EraEdit

From 1865 to 1877, the nation went through Reconstruction. Slavery was abolished, African Americans were made equal citizens with the right to vote, and the South was put under military occupation. The states of the former Confederacy were gradually readmitted into the Union, and most of them elected governments with Republican majorities. However, after the end of Reconstruction in 1877 the South instituted Jim Crow laws designed to oppress and marginalize African Americans. The Southern economy stagnated as it proved unable to adapt to the new Industrial Age.

In the North, agriculture was replaced by manufacturing as the dominant industry. The innovations of electricity, the automobile, the telephone, and the airplane contributed to economic growth which made the United States the world's largest economy by the mid 1870s. Victory in the Spanish-American War firmly established the United States as one of the world's great powers.

World War I and the interwar periodEdit

At the beginning of World War I the United States pursued an isolationist foreign policy. However, civilian deaths from German attacks on American shipping proved unacceptable, and in 1917 the United States entered the war. The fresh American troops quickly proved effective, and Germany was forced to surrender on November 11, 1918.

The 1920s, often referred to as the Roaring Twenties, were a period of progressive reform and economic growth. The 19th Amendment granted suffrage to women, the Washington Naval Arms Treaty limited the sizes of most world navies, and working conditions in factories were improved. On October 29, 1929, the stock market crashed, plunging the United States and later the world into the Great Depression. President Franklin D. Roosevelt's New Deal policies eased unemployment temporarily, but the economy dived again in 1937 and did not recover until the outbreak of war in Europe.

World War IIEdit

The United States was again drawn into war when the Japanese attacked Pearl Harbor on December 7, 1941. Although unsuccessful at first, American naval power triumphed over the Japanese at the Battle of the Coral Sea and the Battle of Midway, and Japan was permanently put on the defensive. On the European front, the failed German invasion of the Soviet Union allowed Allied troops to retake Western Europe after the Normandy landings. Germany surrendered in May of 1945, and Japan on September 2 of the same year after the atomic bombings of Hiroshima and Nagasaki.

Modern eraEdit

After World War II, the United States and the Soviet Union were the only remaining superpowers. The ideological differences between American democracy and Soviet communism resulted in the Cold War. The height of the Cold War, the 1960s, were a tumultuous time for the United States. The country was rocked by the Cuban Missile Crisis, assassination of President John F. Kennedy, the civil rights movement, and the bloody stalemate in Vietnam. The economy tanked in the 1970s with the 1973 oil embargo and the subsequent stagflation. However, by the 1980s the Soviet war in Afghanistan and the democratic reforms of Mikhail Gorbachev had fatally weakened the Soviet Union. In 1991, it dissolved into 15 sovereign states, leaving the US as the sole remaining superpower. 

The swift defeat of Iraq in the Gulf War and a growing economy fueled American self-confidence in the 1990s. This was shattered on September 11, 2001, when al-Qaeda terrorists crashed airliners into major US buildings, killing nearly 3,000 people. In response, the United States invaded Iraq and Afghanistan. The US pulled out of Iraq in 2011, but remains committed to Afghanistan until at least 2014.

Government and politicsEdit

The United States is established as a republic by the United States Constitution, the supreme law of the land. The responsibilities and powers of government are split between the federal, state, and local levels, and within each level there are checks and balances between the executive, legislative, and judicial branches. This arrangement embodies the principles of limited government and separation of powers, as well as limiting corruption and abuse.

The head of state and head of government of the United States is the President of the United States. Presidential elections are held every four years; the President is indirectly elected by the people through the Electoral College. Occasionally, this means that the winner of the popular vote does not win the presidency. No President can serve for more than two terms. The President signs bills into laws, has veto power over bills, and issues executives orders. The President is also commander-in-chief of the military.

The executive branch, which is headed by the President, also has a Cabinet of important government officials, and their corresponding departments. These positions include Secretary of State, Secretary of Defense, and the Attorney General.

The legislative branch, the bicameral Congress, consists of the Senate and the House of Representatives. The Senate has 100 members, two from each state, which are elected by popular vote every 6 years. It is considered the more senior and prestige branch. The House of Representatives has 435 members, proportional to each state's population. Representatives are elected by popular vote every four years. Congress proposes and votes on bills. If a bill passes both houses with a simple majority, it is passed on to the President. The President can either sign or veto the bill. If he vetoes the bill, then Congress can forcibly pass it with a 2/3 majority. Otherwise, it becomes law.

The judicial branch is composed of the Supreme Court of the United States. The Supreme Court rules on the constitutionality of laws in a process called judicial review; since no law can contradict the Constitution, any law found unconstitutional is null and void. It is also the court of final appeal. The Supreme Court has 9 justices, who are nominated by the President and approved by the Senate.

Political divisionsEdit

The United States is a federation of 50 states, one federal district, and several territories. 48 states are part of the contiguous United States, while Hawaii is located in the Pacific Ocean and Alaska is separated from the Lower 48 by Canada. Each state has its own constitution, governor, legislature, and judicial system. However, the federal government and the Constitution remain supreme.

Parties and electionsEdit

There are two major political parties in the United States, the Democratic Party and the Republican Party. The Democratic Party is considered center-left, while the Republican Party is center-right. These two parties hold the vast majority of federal, state, and local government positions. There are also third parties such as the Green Party and the Libertarian Party, who may have limited representation.

Foreign relationsEdit

The foreign policy of the United States is set by Congress and the President and carried out by the United States Department of State. The US maintains bilateral relations with most members of the United Nations.



New York City is the country's largest economic center.

The US economy is primarily a service economy, although it retains relatively large manufacturing and agriculture sectors. It is the largest economy in the world, with a nominal GDP of nearly $15 trillion. Its success has been attributed to bountiful natural resources, a large and well-educated population, and business-friendly government. New York City, particularly Wall Street, is considered the financial capital of the world, being home to both the New York Stock Exchange and NASDAQ.

The Midwestern United States is one of the most agriculturally productive regions on Earth, and the US is a net food exporter. Major crops include corn, soybeans, and wheat. California also has a large agricultural sector; along with Florida, it produces much of the world's citrus fruits.

Manufacturing in the United States was historically based in the Northeastern United States, especially in the Great Lakes region. Although industry has declined since the 1970s, Detroit is still home to many of the world's preeminent automakers, and Pittsburgh remains a major center of steel production.


Main article: Geography of the United States

The United States has a highly varied geography, dominated by large areas of mountains, plains, deserts, taiga, tundra, and temperate forest. It is bounded in the west by the Pacific Ocean, to the east by the Atlantic Ocean, and to the north by the Arctic Ocean.



The Rocky Mountains in Colorado

Among the most prominent features is the North American Cordillera. At its northern tip, it includes Denali, also known as Mount McKinley, which is the highest point in North America at over . Around the US-Canadian border, the mountain chain begins to widen and splits into different ranges. This includes the Cascade Range in the northwestern United States, the Rocky Mountains in Colorado and the Sierra Nevada in California and Nevada. The area between these major ranges is known as the Basin and Range, and occupies almost a sixth of the United States. Most of the basins drain into the Colorado River or evaporate in endorrheic basins.


The Appalachian Mountains

The Appalachian Mountains are located in the eastern United States. They are one of the oldest mountain ranges in the world, estimated at 200-300 million years old. Their highest peak is Mount Mitchell, in North Carolina, which has an elevation of over 6,500 feet. This is also the highest point in the United States east of the Mississippi River. They stretch from northern Georgia to Maine.


North America contains some of the largest river systems in the world. The Mississippi River flows through the heartlands of the United States and empties into the Gulf of Mexico. It was the site of several Civil War battles and is currently a major trade route. The Missouri and Ohio Rivers, which branch off of it, connect much of the eastern United States. The Missouri-Mississippi river system is the longest river in North America and the third longest in the world.

The Rio Grande, known as the Rio Bravo in Mexico, runs along much of the United States-Mexico border in Texas. It is often used by illegal immigrants to enter the United States. The Columbia River in Washington state is a major hydroelectric generator. The Colorado River in the American Southwest is famous for having carved out the Grand Canyon over many millions of years.

Biomes and climateEdit

The biomes and climates of North America vary widely, from arid deserts to arctic tundra. Most of Alaska is dominated by tundra, with permafrost frozen year-round. The mountains of the American West are either a taiga or alpine climate, depending on elevation. Farther south along the mountain ranges, a semi-arid and arid climate takes over. The Mojave and Sonora deserts display typical basin and range topography, with an arid climate that is still wetter than most of the world's deserts.

The Pacific coast has a Mediterranean climate, getting colder and wetter as one progresses north. The Olympic peninsula in Washington state is home to some of the world's only temperate rain forests. The interior of the United States contains the Great Plains, which is one of the world's most productive agricultural regions. This vast steppe continues for thousands of miles, from North Dakota and Montana to Texas and Oklahoma. Vast underwater aquifers help sustain the "breadbasket of the United States", which features mostly corn and wheat production.

Farther to the east of the United States are temperate deciduous forests. The environment there is very similar to that of Western Europe and European settlers found it easiest to adapt to conditions there. While tree cover was reportedly continuous from the Atlantic Ocean to the Mississippi River prior to colonization and large settlement, today the United States Northeast is one of the most built up areas of the country. An axis of urban growth from Washington, DC to Boston includes cities such as Philadelphia and New York and contains more than 50 million people. Farther south, the climate is warmer and categorized as subtropical.



According to the 2010 US Census, the United States has a population of approximately 315 million. This corresponds to a population density of around 80 per square mile. The most populous state is California, with about 38 million inhabitants. Wyoming is the least populous, with around 500,000 denizens. New Jersey is the most densely populated state, while Alaska is the least.


The United States does not have a de jure official language, although English is spoken by a large majority of the population. Chinese, Tagalog, Japanese, Vietnamese, and Korean are spoken by significant immigrant communities. Spanish is spoken both by Hispanic and Latino Americans and as a second language taught in schools. French and German are also widely learnt as a second language.

Most Native American languages have a limited range and declining usage, although Navajo and Cherokee speakers number in the hundreds of thousands each. The Hawaiian language has official status in Hawaii, and Aleut languages are common in Alaska.


The United States is consistently ranked as one of the most religious OECD nations. Most Christian Americans belong to a Protestant denomination, although the Catholic Church is the largest single church by number of followers. Immigrants from Asia and Africa have brought the religions of Islam, Buddhism, and Hinduism, although they remain a minority.


The United States military is one of the largest and most technologically advanced in the world. US military spending dwarfs that of any other nation by a large margin. The military consists of the United States Army, the United States Marine Corps, the United States Air Force, and the United States Coast Guard. It traces its origins to the Continental Army of 1775, formed to fight the British in the American Revolutionary War. It operates hundreds of military bases, both domestically and overseas.

Crime and law enforcementEdit

As with most nations, crime in the United States is disproportionately common in urban areas and especially in low-income neighborhoods. With nearly 2 million in prison, the United States has the largest incarcerated population in the world. This is primarily due to strict drug legislation that imposes heavy penalties for even first-time offenders.

Law enforcement entities exist on the federal, state, and local levels. The primary federal law enforcement agency is the Federal Bureau of Investigation. Others include the Drug Enforcement Administration, the Transportation Security Administration, and Customs and Border Patrol. On the state and local levels, approximately 800,000 police officers are employed in thousands of police departments.


Popular mediaEdit

The United States is a prolific producer of films, music, and television programs. Hollywood has been considered the cinema capital of the world since the 1920s, and has attracted visionary directors such as Orson Welles, Alfred Hitchcock, and Steven Spielberg. American musicians have pioneered many new styles of music, including rock 'n' roll in the 1950s, psychedelic rock in the 1960s, punk rock in the 1970s, and grunge in the 1990s.


Since the American Revolution, the US has cultivated a distinctly American style and introduced many innovations to writing. Early American writers such as Benjamin Franklin, Henry Wadsworth Longfellow, and Washington Irving helped create a community of writers independent of Europe. Transcendentalism, the first major literary movement in the United States, produced influential authors such as Henry David Thoreau and Ralph Waldo Emerson. Edgar Allan Poe, considered one of America's greatest poets, developed the genres of horror and detective fiction. Mark Twain shattered stylistic conventions with his use of the vernacular and his portrayal of controversial topics such as slavery. In the 20th century, authors such as F. Scott Fitzgerald, John Steinbeck, and William Faulkner have won global acclaim and Nobel Prizes in Literature.


The United States has traditionally emphasized sports and athleticism. It has won more Olympic gold medals than any other nation, and is widely considered the dominant nation in American football, baseball, and basketball. It also competes at a high level in hockey and track and field.

The Big Four professional sports leagues in the United States are the National Football League, Major League Baseball, the National Basketball Association, and the National Hockey League. Professional baseball has the most total viewers per season due to the large number of games, while football has the highest number of viewers per game. Basketball and hockey attract smaller, although still significant audiences.