Nine colonies sent delegates to the Stamp Act Congress in New York in 1765.
The congress met from October 7 to October 25 to coordinate colonial opposition to the Stamp Act, a British tax on printed materials. Delegates came from Massachusetts, Rhode Island, Connecticut, New York, New Jersey, Pennsylvania, Delaware, Maryland, and South Carolina.
The meeting produced a Declaration of Rights and Grievances. Its members argued that the colonies could not be taxed by a Parliament in which they had no elected representatives. The congress sent petitions to the king and Parliament, helping establish a pattern of intercolonial cooperation that later became important during the independence movement.
Four colonies—New Hampshire, North Carolina, Virginia, and Georgia—did not send delegates. Their absence does not mean they supported the Stamp Act; royal governors or local circumstances prevented their legislatures from selecting representatives. The event therefore involved nine of the eventual Thirteen Colonies, not all thirteen.