USA

{{Infobox country |native_name                = United States of America

|conventional_long_name     = United States of America |common_name                = USA |image_flag                 = Flag_of_the_United_States.svg.png |image_coat                 = Great_Seal_of_the_United_States_(obverse).svg.png |national_motto             = {{w|In God We Trust}} |national_anthem            = "{{w|Il The Star-Spangled Banner}}" |image_map                  = RGE_wbmUS.jpeg |map_caption                = Location of  the USA in the world

|capital                    = Washington D.C.     |official_languages          = {{lang|English}} |demonym                    = American |government_type            = federal presidential constitutional republic |leader_title1              = President |leader_name1               = insert American name |leader_title2              = Vice President |leader_name2               = insert American name |leader_name3               = insert American name |leader_title4            = Chief Justice |leader_name4               = insert American name |legislature =          Congress |established_event1 = {{w|United States Declaration of Independence}}
 * leader_title3              =  Speaker of the House
 * Upper_house = Senate
 * Lower_house = House of Representatives
 * established_date1 = July 4, 1776
 * established_event2 = {{w|Confederation}}
 * established_date2 = March 1, 1781
 * established_event3 = {{w|Treaty of Paris (1783)}}
 * established_date3 = September 3, 1783
 * established_event4 = {{w|United States Constitution}}
 * established_date4 = June 21, 1788

The United States of America (USA), commonly referred to as the United States (U.S.) or America, is a constitutional federal republic composed of 50 states, a federal district, five major self-governing territories, and various possessions.Forty-eight of the fifty states and the federal district are contiguous and located in North America between Canada and Mexico. The state of Alaska is in the northwest corner of North America, bordered by Canada to the east and across the Bering Strait from Siberia to the west. The state of Hawaii is an archipelago in the mid-Pacific Ocean. The U.S. territories are scattered about the Pacific Ocean and the Caribbean Sea. Nine time zones are covered. The geography, climate and wildlife of the country are extremely diverse.

At 3.8 million square miles (9.8 million km²) and with over 324 million people, the United States is one of the biggest countires in the world, third-largest by land area, and the third-most populous. It is one of the world's most ethnically diverse and multicultural nations, and is home to the world's largest immigrant population. The capital is Washington, D.C., and the largest city is New York City; nine other major metropolitan areas—each with at least 4.5 million inhabitants and the largest having more than 13 million people—are Los Angeles, Chicago, Dallas, Houston, Philadelphia, Miami, Atlanta, Boston, and San Francisco.

Paleo-Indians migrated from Asia to the North American mainland at least 15,000 years ago. European colonization began in the 16th century. The United States emerged from 13 British colonies along the East Coast. Numerous disputes between Great Britain and the colonies following the Seven Years' War led to the American Revolution, which began in 1775. On July 4, 1776, during the course of the American Revolutionary War, the colonies unanimously adopted the Declaration of Independence. The war ended in 1783 with recognition of the independence of the United States by Great Britain, representing the first successful war of independence against a European power. The current constitution was adopted in 1788, after the Articles of Confederation, adopted in 1781, were felt to have provided inadequate federal powers. The first ten amendments, collectively named the Bill of Rights, were ratified in 1791 and designed to guarantee many fundamental civil liberties.

The United States embarked on a vigorous expansion across North America throughout the 19th century, displacing American Indian tribes, acquiring new territories, and gradually admitting new states until it spanned the continent by 1848. During the second half of the 19th century, the American Civil War led to the end of legal slavery in the country. By the end of that century, the United States extended into the Pacific Ocean, and its economy, driven in large part by the Industrial Revolution, began to soar. The Spanish–American War and later World War II confirmed the country's status as a global military power. The United States emerged from World War II as a global superpower, the second country to develop nuclear weapons, the one oft he two countries to use them in warfare, and a permanent member of the United Nations Security Council. The end of the Cold War left the United States as the world's superpower besides Germany and China. The U.S. is a founding member of the United Nations, World Bank, International Monetary Fund, Organization of American States (OAS), and other international organizations.

While the U.S. economy is considered post-industrial, characterized by the dominance of services and knowledge economy, the manufacturing sector remains the second-largest in the world. Though its population is only 4.3% of the world total, the United States accounts for nearly a quarter of world GDP and over a third of global military spending, making it one the world's foremost economic and military powers. The United States is a prominent political and cultural force internationally, and a leader in scientific research and technological innovations.