Thirteen British colonies united in declaring independence and forming the United States in 1776.
The colonies stretched along the Atlantic coast of North America and were grouped as New England, Middle, and Southern colonies. They included Virginia, Massachusetts, Pennsylvania, Georgia, and ten others that joined the revolutionary movement.
The colonies had separate governments and local political traditions, but disputes with Britain over taxation, representation, and imperial control encouraged cooperation. Delegates from the colonies created the Continental Congress and coordinated resistance.
The number thirteen is easy to confuse with the thirteen stripes on the original American flag, but the flag symbolism followed the colonial count. The colonies became states through the Revolutionary era, while new states were admitted later under the Constitution.