Open warfare erupted when British regulars sent to capture a cache of military supplies were confronted by local Patriot militia at Lexington and Concord on April 19, 1775. Patriot militia, joined by the newly formed Continental Army, then put British forces in Boston under siege. Each colony formed a Provincial Congress, which assumed power from the former colonial governments, suppressed Loyalism, and contributed to the Continental Army led by General George Washington. The Continental Congress declared King George III a tyrant who trampled the colonists' rights as Englishmen, and they declared the colonies free and independent states on July 2, 1776. The Patriot leadership professed the political philosophies of liberalism and republicanism to reject monarchy and aristocracy, and they proclaimed that all men are created equal.