The American Revolutionary War (April 19, 1775 – September 3, 1783), also known as the Revolutionary War or American War of Independence, was the military conflict of the American Revolution in which American patriot forces under George Washington's command defeated the British, establishing and securing the independence of the United States. Fighting began on April 19, 1775, at the Battles of Lexington and Concord. The war was formalized and intensified following passage of the Lee Resolution on July 2, 1776, which asserted that the Thirteen Colonies were "free and independent states", and the Declaration of Independence, drafted by the Committee of Five and written primarily by Thomas Jefferson, two days later, on July 4, 1776, by the Second Continental Congress in Philadelphia. In the war, American patriot forces were supported by the Kingdom of France and, to a lesser extent, the Kingdom of Spain and the Dutch Republic. The British were supported by Hessian soldiers from present-day Germany. The conflict was fought in North America, the Caribbean, and the Atlantic Ocean. Established by Royal charter in the 17th and 18th centuries, the American colonies were largely autonomous in domestic affairs and commercially prosperous, trading with Britain and its Caribbean colonies, as well as other European powers via their Caribbean entrepôts. After British victory over the French in the Seven Years' War in 1763, tensions between the motherland and her 13 colonies arose over trade, policy in the Northwest Territory, and taxation measures, including the Stamp Act and Townshend Acts. Colonial opposition led to the Boston Massacre in 1770 which largely fostered the idea of independence from Britain. While the earlier taxation measures were repealed, Parliament adopted the Tea Act in 1773, a measure that led to the Boston Tea Party on December 16. In response, Parliament imposed the so-called Intolerable Acts in mid-1774, closing the Boston Harbor, revoking Massachusetts' charter, and placing the colony under control of the British government. The measures stirred unrest throughout the colonies, 12 of which sent delegates to Philadelphia in early September 1774 to organize a protest as the First Continental Congress. In an appeal to Britain's George III seeking peace, the Congress drafted a Petition to the King but also threatened a boycott of British goods known as the Continental Association if the Intolerable Acts were not withdrawn. Despite attempts to achieve a peaceful solution, fighting began, after the Westminster Massacre in March, with