Thirteen colonies became the original United States in 1776.
The colonies were New Hampshire, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, Pennsylvania, Delaware, Maryland, Virginia, North Carolina, South Carolina, and Georgia. Their delegates acted through the Second Continental Congress and adopted the Declaration of Independence in July 1776.
The phrase “Thirteen Colonies” refers to the British colonies along the Atlantic coast that rebelled together. It does not mean that every British possession in North America joined the new country. Quebec, Nova Scotia, Florida, and other territories remained outside the United States at independence.
The thirteen states also formed the first Union under the Articles of Confederation. Each state retained a distinct identity and government, a feature that shaped later debates over federal and state authority. The number thirteen remained symbolically important: the first United States flag had thirteen stars and thirteen stripes, although its design changed over time as new states joined.