United States of America

The United States of America (U.S.A or USA), commonly known as the United States (U.S. or US) or America is a nation primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, 326 Indian reservations and some minor possessions. It is the fourth largest country by area.It has a population of 331 million people making it the third most populous country in the world.The capital city is Washington D.C. and the most populous city is New York City. Paleo-Indians migrated from Siberia to North America at least 12,000 years ago, and European colonization of the present day U.S. began in the late 1500s. The United States emerged from the Thirteen colonies from Britain during the American Revolutionary War (1775-1783). In the 18th century, the U.S. went on a massive expansion west of the Mississippi, acquiring new territories, often displacing Native Americans and admitting new states. By 1848, the U.S.spanned the continent. The American Civil War in the early 1860s led to the abolition of slavery. The Spanish-American War World War I established the U.S. as a world power which was confirmed from the outcome of World War II. During the Cold War, the U.S, fought both the Korean and Vietnam Wars but avoided direct conflict with the Soviet Union. The two superpowers competed in the Space Race, ending with the 1969 spaceflight that landed humans on the Moon for the first time. the Soviet Union's dissolution in 1991 ended the Cold War, leaving the U.S. as the world's sole superpower. The United States is a federal republic and a representative democracy with three separate branches of government. It is a founding member of the United Nations, World Bank, International Monetary Fund, Organization of American States, NATO and other international organizations.