United States Declaration of Independence

The United States Declaration of Independence was an act of the Second Continental Congress, adopted on July 4, 1776, which declared that the Thirteen Colonies were independent of the Kingdom of Great Britain. The document, formally entitled The unanimous Declaration of the thirteen united States of America and written chiefly by Thomas Jefferson, explained the justifications for separation from the British crown, and was an expansion of Richard Henry Lee's Resolution (passed by Congress on July 2), which first proclaimed independence. An engrossed copy of the Declaration was signed by most of the delegates on August 2 and is now on display in the National Archives and Records Administration in Washington, D.C.

The Declaration is considered to be a preceding founding document of the later formed United States of America, where July 4 is celebrated as Independence Day. At the time the Declaration was issued, the American colonies were "united" in declaring their independence from Great Britain, but were not yet declaring themselves to be a single nation. That union would evolve and take shape during the next few years after the Declaration was issued.

US President Abraham Lincoln succinctly explained the central importance of the Declaration to American history in his Gettysburg Address of 1863: