Which document announced the separation of the thirteen colonies from Great Britain?

The correct answer is the Declaration of Independence because this document was specifically created to formally announce and justify the separation of the thirteen American colonies from British rule. Drafted primarily by Thomas Jefferson in 1776, it outlines the colonies' grievances against King George III and articulates the philosophical rationale for independence, emphasizing the rights to life, liberty, and the pursuit of happiness.

In contrast, the Constitution serves as the framework for the United States government established after independence; the Articles of Confederation were the first system of governance for the new nation but were ultimately deemed inadequate; the Bill of Rights comprises the first ten amendments to the Constitution, detailing individual liberties and protections, and was adopted later to address concerns about the government's power over citizens. Therefore, the Declaration of Independence uniquely serves as the foundational document that marks the colonies' break from Britain.