Here’s the story according to paulreverehouse.org: “In 1774 and the Spring of 1775 Paul Revere was employed by the Boston Committee of Correspondence and the Massachusetts Committee of Safety as an express rider to carry news, messages, and copies of resolutions as far away as New York and Philadelphia.
“On the evening of April 18, 1775, Revere was sent for by Dr. Joseph Warren and instructed to ride to Lexington, Massachusetts, to warn Samuel Adams and John Hancock that British troops were marching to arrest them.
“After being rowed across the Charles River to Charlestown by two associates, Revere borrowed a horse from his friend Deacon John Larkin. While in Charlestown, he verified that the local Sons of Liberty committee had seen his pre-arranged signals. Two lanterns had been hung briefly in the bell-tower of Christ Church in Boston, indicating that troops would row “by sea” across the Charles River to Cambridge rather than marching “by land” out Boston Neck.
“On the way to Lexington, Revere alarmed the countryside, stopping at each house, and arrived in Lexington about midnight. As he approached the house where Adams and Hancock were staying, a sentry asked that he not make so much noise. ‘Noise!’ cried Revere, ‘You’ll have noise enough before long. The regulars are coming out!’
“After delivering his message, Revere was joined by a second rider, William Dawes, who had been sent on the same errand by a different route. Deciding on their own to continue on to Concord, Massachusetts, where weapons and supplies were hidden, Revere and Dawes were joined by a third rider, Dr. Samuel Prescott. Soon after, all three were arrested by a British patrol. Prescott escaped almost immediately, and Dawes soon after. Revere was held for some time and then released. Left without a horse, Revere returned to Lexington in time to witness part of the battle on the Lexington Green.”