The Declaration of Independence is a historic document adopted on July 4, 1776, by the Second Continental Congress in Philadelphia. It announced the thirteen American colonies' decision to break away from British rule, asserting their right to self-governance and independence. The document outlines key principles, including the belief that all people have certain unalienable rights, such as life, liberty, and the pursuit of happiness. It also lists grievances against King George III, justifying the colonies' separation from Great Britain and establishing the foundation for the formation of the United States of America.