Which document formally established the United States' independence from Britain?

The document that formally established the United States' independence from Britain is the Declaration of Independence. Adopted on July 4, 1776, it was a revolutionary statement drafted primarily by Thomas Jefferson, which announced the colonies' separation from British rule. The Declaration articulates key principles of individual liberty and government by consent, asserting the right of the colonies to be free and independent states. It also lists grievances against King George III, justifying the break with Britain and asserting the colonies' right to self-governance. This pivotal document not only marked the birth of the United States as a nation but also sparked democratic movements around the world, highlighting the importance of liberty and self-determination.