The Battles of Lexington and Concord began on April 19, 1775.
British troops marched from Boston to seize colonial military supplies reportedly stored at Concord. Patriot intelligence networks learned of the expedition, and riders including Paul Revere, William Dawes, and Samuel Prescott warned local communities during the night.
At sunrise, British regulars encountered Massachusetts militia on Lexington Common. Fighting then spread to Concord, where colonists resisted at the North Bridge. During the British retreat to Boston, growing numbers of militia fired from the roadside and inflicted substantial casualties.
The battles are widely regarded as the first major military actions of the American Revolutionary War. The Lexington encounter was a brief skirmish, while the day-long operation extended across several communities. The phrase “shot heard round the world” later became associated with the opening of the conflict, especially through Ralph Waldo Emerson’s 1837 poem about Concord.