The Battles of Lexington and Concord began on April 19, 1775, marking the first major military actions of the American Revolutionary War.
British troops marched from Boston to Concord to seize colonial military supplies. Patriot riders, including Paul Revere, William Dawes, and Samuel Prescott, had warned local militia that the expedition was approaching. At sunrise, British regulars and Massachusetts militiamen confronted one another on Lexington Common.
The fighting continued at Concord, especially at the Old North Bridge, before the British column began its return to Boston. Patriot militia fired on the retreating soldiers from the surrounding countryside, causing substantial British casualties. The clashes helped turn political resistance into open warfare.
The first shot at Lexington is often called the “shot heard round the world,” but historians cannot establish with certainty who fired it. The date is also sometimes confused with April 18, when the British expedition began moving and the warning rides took place.