Which event is recognized as the first major military action of the American Revolutionary War?

The Battles of Lexington and Concord were the first major military actions of the American Revolutionary War.

Fighting began on April 19, 1775, when British troops marched from Boston toward Concord to seize colonial military supplies. Patriot riders had warned local militias, and armed confrontations occurred first at Lexington and then at Concord’s Old North Bridge. The British column later faced sustained fire during its retreat toward Boston.

These engagements transformed political resistance into open warfare. The clashes also began the Siege of Boston, as Massachusetts militia forces surrounded the British garrison. Although the Lexington encounter was a brief skirmish, the linked actions across several communities became the war’s recognized opening battle.

The phrase “shot heard round the world” is associated with the opening at Lexington and Concord, especially through Ralph Waldo Emerson’s later poem “Concord Hymn.” The battles happened more than a year before the Declaration of Independence was adopted.