The Powder Alarm was the 1774 event reenacted in Somerville, Massachusetts, during preparations for America250.
The incident began on September 1, 1774, when British troops removed colonial gunpowder from a magazine near Boston. The operation was ordered by General Thomas Gage, the military governor of Massachusetts, and involved roughly 260 British regulars.
False reports that fighting had begun spread rapidly through the countryside. Thousands of colonial militiamen mobilized and moved toward Boston and Cambridge, although the crisis eventually subsided without the bloodshed many people feared. The event became an important warning that armed conflict was approaching.
Historians often describe the Powder Alarm as a rehearsal for the Battles of Lexington and Concord, which occurred about seven and a half months later. Somerville and nearby Cambridge marked its 250th anniversary with reenactment and educational activities in 2024, ahead of the United States’ 250th anniversary in 2026.