The American Revolution (1775-1783) was the struggle by which the Thirteen Colonies were to become the United States, winning independence from Britain. By the middle of the 18th cent., differences in life, thought, and economic interests had formed between the colonies and the mother country. The British government, favoring a policy of mercantilism, tried to regulate colonial commerce in the British interest, and provoked colonial opposition. The Stamp Act passed by Parliament in 1765 roused a violent colonial outcry as an act of taxation without representation. The Townshend Acts (1767) led to such acts of violence as the Boston Massacre (1770), the burning of the H.M.S. Gaspee (1772), and the Boston Tea Party (1773). In 1774 Britain responded with the coercive Intolerable Acts. The colonists convened the Continental Congress and petitioned the king for redress of their grievances. Fighting erupted on Apr. 19, 1775, at Lexington and Concord, and was followed by the capture of Fort Ticonderoga from the British, the battle of Bunker Hill, and the unsuccessful colonial assault on Quebec (1775-76). The Continental Congress appointed (1775) George Washington to command the Continental army and, on July 4, 1776, adopted the Declaration of Independence. Many colonists, however, remained pro-British Loyalists. The colonial victory in the Saratoga campaign (1777) helped forge a French-American alliance (1778), bringing vital aid to the colonists. Following the terrible ordeal of Washingon's army at Valley Forge and the indecisive battle of Monmouth (1778), the war shifted to the South during the Carolina campaign (1780-81). The surrender (Oct. 1781) of Gen. Cornwallis at the close of the Yorktown campaign ended the fighting, and the Treaty of Paris (1783) recognized the U.S. as a nation.