The phrase The shot heard round the world signifies the start of the American Revolution, referring specifically to the first gunfire exchanged at the battles of Lexington and Concord on April 19, 1775.

This crucial moment signified the shift from political strife to armed conflict, highlighting the colonies' resolve to oppose British rule. The phrase captures the significant influence of this event, as it not only sparked the fight for independence in America but also reverberated around the world, motivating other movements for freedom and self-determination.