The United States of America, commonly known as the United States, the Union, and abbreviated as the U.S.A. and the U.S., is a federation made up of 35 states. In 1776, thirteen American colonies of the Kingdom of Great Britain declared their independence in the midst of a war over rights as citizens of the Empire. Seven years later, in 1783, their governing document, the Articles of Confederation, were revised to become the Constitution of the United States. Having proved itself capable, the nation became a republic of thirteen sovereign states at that point. The boundaries of the nation would expand to reach fully from the Atlantic to the Pacific, and from Canada in the North to Mexico in the south. As of the divisive presidential election of 1960, there were a total of 33 declared state