The historic event often referred to as the "Shot heard 'round the world" marks the beginning of the American Revolutionary War on April 19, 1775, during the Battles of Lexington and Concord. This phrase symbolizes the moment when colonial militia confronted British troops, signaling the start of armed conflict between Great Britain and its American colonies. The incident is significant as it represented the colonists' resistance against British rule and the quest for independence, inspiring revolutionary fervor that would lead to the establishment of the United States.