The Old North Church played a crucial role in signaling the British advance during the events leading up to the battles of Lexington and Concord.

On the evening of April 18, 1775, patriots, among them Paul Revere, utilized the church steeple to signal with two lanterns as a warning system. This conveyed the message that British forces were advancing by sea; one lantern indicated an overland route, while two signaled a maritime approach. This form of communication was crucial in notifying the colonial militias, enabling them to ready themselves for the looming conflict and swiftly mobilize against the British troops.