Thirteen British colonies declared independence in the Declaration of Independence.
The colonies were New Hampshire, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, Pennsylvania, Delaware, Maryland, Virginia, North Carolina, South Carolina, and Georgia. Together they formed the United States after separating from Great Britain.
The Declaration refers to the colonies as the “United Colonies” in its opening and closing sections. They were not yet states in the fully established constitutional sense, although the document’s final wording described them as free and independent states.
The thirteen colonies are sometimes confused with the later number of states in the Union. Vermont became the fourteenth state in 1791, followed by Kentucky in 1792, so the United States quickly expanded beyond the original thirteen.