The United States Declaration of Independence declared 13 colonies independent in 1776.
Those colonies were New Hampshire, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, Pennsylvania, Delaware, Maryland, Virginia, North Carolina, South Carolina, and Georgia. The document described them as free and independent states rather than colonies of Great Britain.
The Second Continental Congress represented the colonies in Philadelphia. On July 2, it passed the Lee Resolution declaring independence; on July 4, it approved the fuller Declaration explaining the decision and listing grievances against King George III.
The number 13 remained important after independence. The first United States flag adopted by Congress in 1777 had 13 stars and 13 stripes, representing the original states. The modern flag still has 13 stripes, while its stars increased as new states joined the Union. The 13 colonies should not be confused with the 50 states that make up the United States today.