Thirteen colonies declared independence together in the United States' founding era.
The colonies were New Hampshire, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, Pennsylvania, Delaware, Maryland, Virginia, North Carolina, South Carolina, and Georgia. They formed the political core of the United States during the American Revolution.
The colonies did not all have identical governments, economies, or populations. New England, the Middle Colonies, and the Southern Colonies developed different social and economic patterns, yet their representatives eventually joined in resistance to British rule and created a common revolutionary government.
The number 13 refers to Britain's mainland North American colonies that became the original United States. It does not include every British possession in North America, and it should not be confused with the 13 stripes on the modern American flag, which symbolize the same original states.