The historical document that declared independence from Britain is the Declaration of Independence, adopted by the Continental Congress on July 4, 1776. This document marked the thirteen American colonies' decision to break free from British rule. It was authored primarily by Thomas Jefferson, with input from other founding fathers. The Declaration articulates the colonies' grievances against King George III and outlines the philosophical justification for independence, emphasizing the principles of individual rights and governmental consent. Its adoption is celebrated annually on Independence Day in the United States, symbolizing the birth of a new nation based on democratic ideals.