What were the battles of Lexington and Concord?

The battles of Lexington and Concord were the first military engagements of the American Revolutionary War, fought on April 19, 1775 in two Massachusetts villages northwest of Boston. General Thomas Gage, who governed Massachusetts under martial provisions of the Coercive Acts, received secret orders dated January 27, 1775 from Lord Dartmouth in London to use force against the rebellious provincial congress and to seize military stores. On the night of April 18, Gage sent about 700 British regulars under Lieutenant Colonel Francis Smith and Major John Pitcairn to march from Boston to Concord, where colonial militia had been stockpiling muskets, gunpowder, cannon, and provisions.

Patriot scouts including Joseph Warren learned of the plan, and shortly before midnight Paul Revere and William Dawes left Boston by separate routes to warn Lexington and Concord. Revere reached Lexington around midnight to alert Samuel Adams and John Hancock, then continued toward Concord with Dawes and Dr. Samuel Prescott; Revere was captured by a British patrol but Prescott reached Concord. At dawn on April 19 about 77 militiamen under Captain John Parker assembled on Lexington Green facing the advancing British column. Parker's exact words are lost, but tradition holds he told them to stand their ground and not fire unless fired upon, with the words "if they mean to have a war, let it begin here." A shot rang out, the famous shot heard round the world, and the British fired volleys that killed eight militiamen and wounded ten before the regulars marched on.

At Concord, militia from Concord, Acton, Lincoln, and Bedford gathered on Punkatasset Hill above the North Bridge. After British soldiers searching the town set fires that the militia thought were burning the village, Major John Buttrick gave the order to fire, and Concord militia killed two regulars and wounded several at the bridge in the first organized colonial volley aimed at British troops. The British turned back to Boston after a frustrating search that yielded little, and the long return march turned into a bloody running fight as militia from across Middlesex County fired from behind walls and trees. By nightfall the British had suffered 73 killed, 174 wounded, and 26 missing, and the Americans had 49 killed and 39 wounded.

Boston was suddenly besieged by an army of 15,000 New England militia. The Second Continental Congress convened three weeks later, named George Washington commander of the Continental Army, and the Revolutionary War had begun.