Special militia units able to be called to arms "at a minute's notice," the Minutemen first were organized by the Massachusetts provincial congress in 1774. The first of these units fought at the Battles of Lexington and Concord. Other colonies formed such units. The Lexington-Concord battle touched off the American Revolution, following British Gen. Thomas Gage's orders to seize gunpowder stored by Massachusetts at Concord. Paul Revere's ride, and that of his colleagues, to summon the minutemen allowed time to remove most of the gunpowder. The minutemen then began to assault the British on their return to Boston, inflicting 273 casualties.