The United States of America is a presidential republic comprising of thirty-five states and a federal district. The country is situated in central North America, where its thirty-five states and Washington, D.C., the capital district, lie between the Pacific and Atlantic Oceans, bordered by Canada to the north, Mexico, and the Confederate States of America to the south.
The nation was founded by thirteen colonies of Great Britain located along the Atlantic seaboard. On July 4, 1776, they issued the Declaration of Independence, which proclaimed their independence from Great Britain and their formation of a cooperative union. The rebellious states defeated Great Britain in the American Revolutionary War. A federal convention adopted the former United States Constitution on September 17, 1787. However, this Constitution was replaced by the New United States Constitution on July 11, 1872, due to the perceived failure of the previous government. This discontent followed the secession of the southern states to form the Confederate States of America. Its victories in World War I and World War II confirmed the nation's status as a military power. In 1945, the United States obtained nuclear weapons and also helped found the United Nations. In today's world, the United States is an economic, political, and cultural force.