The event commonly referred to as the "shot heard 'round the world" marks the start of the American Revolutionary War. It occurred on April 19, 1775, during the battles of Lexington and Concord in Massachusetts. This phrase signifies the first armed conflict between the American colonists and British troops, symbolizing the beginning of the struggle for American independence. Though the actual shot was fired by an unknown individual, its consequences were profound, rallying support for the revolutionary cause and igniting a political movement against British rule that ultimately led to the founding of the United States.