The battle in 1775 that marked the beginning of the American Revolutionary War was the Battle of Lexington and Concord. This conflict occurred on April 19, 1775, when British troops were dispatched to confiscate colonial military supplies. Colonists, alerted by figures like Paul Revere, confronted the British at Lexington, where the "shot heard 'round the world" was fired. This skirmish ignited armed resistance and led to a series of confrontations, rallying colonial unity against British rule. The battles resulted in significant casualties and marked a shift toward a full-scale revolution, playing a crucial role in the subsequent fight for American independence.