What founding document said the American colonies were free from Britain?

Why this is the answer

The document is the Declaration of Independence. The Second Continental Congress adopted it on July 4, 1776, and its purpose was exactly what its name says: to declare that the thirteen colonies were no longer part of Great Britain. The Constitution is the other founding document people mix it up with, but it came eleven years later, in 1787, and its job was different: to organize the government of a country that already existed. Memory hook: the Declaration says "we are free"; the Constitution says "this is how we govern ourselves".