Patriots’ Day, celebrated in Massachusetts on April 15, commemorates the beginning of the American Revolution at the Battles of Lexington and Concord in 1775. The evening before that pivotal conflict took place, however, a signal was sent by famed midnight rider Paul Revere to his rebellious compatriots across the Charles River warning them of the approaching Redcoats. The placing of this beacon—the renowned “two if by sea” twin lanterns—occurred in the steeple of the Old North Church, an event that has been recreated at the historic house of worship’s annual Lantern Ceremony since 1875, and takes place this year on April 14. Join your fellow history buffs from 7–8 p.m. for a reenactment, a reading of Longfellow’s poem “Paul Revere’s Ride” and a keynote address by the state’s attorney general, Maura Healey.