United States

The  United States of America  or America, is a country primarily located in North America. It consists of 50 states, a federal district, five large unincorporated territories, 326 Indian reservations, and some minor holdings. Covering 3.8 million square miles (9.8 million square kilometers), it is the third or 4th largest country globally in terms of total area. The United States has significant land borders with Canada to the north and Mexico to the south and limited maritime borders. with the Bahamas, Cuba and Russia. With a population of over 331 million, it is the third most populous country in the world. The capital of the country is Washington, DC, and the most populous city is New York.

Paleo-Indians migrated from Siberia to mainland North America at least 12,000 years ago, and European colonization began in the 16th century. The United States originated from thirteen British colonies based on the East Coast. Disputes with Britain over taxation and political representation led to the US War of Independence (1775–1783), which established the country's independence. In the late 18th century, the United States began to expand across North America, gradually conquering new territories, sometimes as a result of war, often displacing Native Americans and accepting new states; by 1848, the United States had swept the continent. Slavery was legal in the southern United States until the second half of the 19th century, when the American Civil War led to its abolition. The Spanish-American War and World War I made the United States a world power, and the results of World War II confirmed this status. During the Cold War, the United States fought the Korean War and the Vietnam War, but avoided direct military conflict with the Soviet Union. The two superpowers competed in a space race that culminated in the 1969 space flight, in which humans landed on the moon for the first time. The collapse of the Soviet Union in 1991 ended the Cold War, leaving the United States as the world's only superpower.

The United States is a federal republic and a representative democracy with three separate branches of government, including a bicameral legislature. He is a founding member of the United Nations, World Bank, International Monetary Fund, Organization of American States, NATO and other international organizations. He is a permanent member of the UN Security Council. Considered a melting pot of cultures and ethnic groups, its population has been profoundly shaped by centuries of immigration. The United States ranks high on international indicators of economic freedom, quality of life, education, and human rights; it has a low level of perceived corruption. However, the country has been criticized for inequality related to race, wealth and income, the death penalty use, high incarceration rates; and the lack of universal health care.

The United States is a highly developed country, accounting for about a quarter of world GDP, and is the world's largest economy by GDP at market exchange rates. The United States is the world's largest importer and second largest exporter of goods in terms of value. Although it accounts for only 4.2% of the world's total population, it accounts for 29.4% of the world's total wealth, which is the largest share owned by any country. It accounts for more than a third of the world's military spending, and is the world's leading military power and the leading political, cultural and scientific power at the international level.