The significance of the Battle of Lexington and Concord lies in its role as the first military engagements of the American Revolutionary War. Fought on April 19, 1775, these battles marked the beginning of armed conflict between colonial militias and British troops. The skirmishes ignited a larger revolutionary movement against British rule, as they demonstrated the colonies' willingness to fight for their rights. The phrase "the shot heard 'round the world" encapsulates the global impact of this rebellion, inspiring other nations seeking independence and laying the groundwork for the eventual establishment of the United States.