The document that declared the independence of the thirteen American colonies from British rule is the Declaration of Independence, adopted on July 4, 1776. Drafted primarily by Thomas Jefferson, the Declaration outlines the colonies’ grievances against King George III and articulates the philosophical foundations of independence, emphasizing the principles of individual liberty and the right to self-govern. This revolutionary document was a bold assertion of the colonies’ desire for autonomy and was instrumental in galvanizing support for the American Revolutionary War. Its enduring legacy lies in its articulation of democratic ideals that continue to influence democratic movements worldwide.