Which event formally marked the separation between Great Britain and the American colonies?

The signing of the Declaration of Independence formally marked the separation between Great Britain and the American colonies. This pivotal event took place on July 4, 1776, when the thirteen colonies asserted their right to be free and independent states, no longer under British rule. The document, primarily authored by Thomas Jefferson, outlined the colonies' grievances against King George III and articulated the foundational principles of individual rights and government by consent.

While other events, such as the Revolutionary War and the Boston Tea Party, played significant roles in the struggle for independence, they did not in themselves symbolize the formal declaration of separation. The Revolutionary War was a consequence of the Declaration and a means to achieve the independence that was proclaimed. The Boston Tea Party was an act of protest against British taxation but did not represent a formal break. The signing of the Constitution occurred much later and was focused on establishing the structure of the new government rather than declaring independence from Britain.