Two lanterns were hung in Boston’s Old North Church during Paul Revere’s warning operation in April 1775.
The lantern signal indicated that British troops were moving by sea rather than entirely by land: “one if by land, and two if by sea.” Robert Newman, the church sexton, and Captain John Pulling placed the lanterns in the church steeple on the night of April 18, 1775.
Paul Revere had arranged the signal as part of a broader warning network. He then crossed the Charles River by boat and rode through nearby communities, alerting colonial leaders that British troops were marching toward Lexington and Concord.
The popular story often treats Revere as the only rider, but William Dawes and Samuel Prescott also carried warnings. Revere was captured before reaching Concord, while Prescott escaped and continued the alarm.