Thirteen British colonies joined to form the United States in the 1776 Declaration of Independence.
The colonies stretched along the Atlantic coast and were commonly grouped as New England, Middle, and Southern colonies. They were separately administered, but shared political and legal traditions that helped their representatives coordinate during the crisis with Britain.
The New England group included New Hampshire, Massachusetts, Rhode Island, and Connecticut. The Middle Colonies included New York, New Jersey, Pennsylvania, and Delaware. Maryland, Virginia, North Carolina, South Carolina, and Georgia made up the Southern group.
The number thirteen appears repeatedly in early American symbols, including the original flag's stars and stripes. It refers to the colonies that declared independence, not to every British colony in North America. British territories such as Nova Scotia, Quebec, and the Floridas did not join the new United States.