The 1776 United States Declaration of Independence united 13 colonies against Britain.
Those colonies were New Hampshire, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, Pennsylvania, Delaware, Maryland, Virginia, North Carolina, South Carolina, and Georgia. They became known collectively as the Thirteen Colonies and later formed the original states of the United States.
The colonies did not all move toward independence at exactly the same pace. The Second Continental Congress passed the Lee Resolution on July 2, 1776, and adopted the explanatory Declaration two days later. The Declaration stated that the colonies were free and independent states rather than subjects of the British Crown.
The phrase “13 colonies” describes the British colonies that declared independence, not the number of signers or the number of states in the United States today. Fifty-six delegates eventually signed the Declaration, while the modern United States has 50 states.