Map of the United States with its states and capitals

The United States is a federal union of fifty states. The thirteen original states were the successors of the Thirteen colonies that rebelled against the British Empire. Shortly after independence, three new states were created from existing ones: Kentucky of Virginia; Tennessee of North Carolina and Maine of Massachusetts. Most of the other states were created from territories obtained through war or purchase by the government. Vermont, Texas and Hawaii are the exception: each of them was an independent republic before joining the Union. During the Civil War, West Virginia separated from Virginia. The most recent state is Hawaii, which achieved recognition as a state on August 21, 1959. States do not have the right to secede from the Union.

The states make up a large part of the US territory; the other two areas that are considered an integral part of the country are the District of Columbia, the Federal District where the capital Washington DC is located, and the Palmyra Atoll, an uninhabited but incorporated territory located in the Pacific Ocean. The United States also has five major overseas territories: Puerto Rico and the United States Virgin Islands in the Caribbean and American Samoa, Guam and the Northern Mariana Islands in the Pacific. Those who were born in those territories (except for American Samoa) have American citizenship. US citizens residing in the territories have many of the rights and responsibilities of citizens residing in the states; however, they are generally exempt from paying federal taxes, cannot vote in presidential elections and only have representation as observers in Congress.