The Powder Alarm was a massive popular reaction to the removal of gunpowder from a magazine by British soldiers under orders from General Thomas Gage, royal governor of the Province of Massachusetts Bay, on September 1, 1774.
In response to this action, amid rumors that blood had been shed, alarm spread through the countryside as far as Connecticut, and American Patriots sprang into action, fearing that war was at hand.
Although it proved to be a false alarm, the Powder Alarm caused political and military leaders to proceed more carefully in the days ahead, and essentially provided a "dress rehearsal" for the Battle of Lexington and Concord seven months later. Furthermore, actions on both sides to control weaponry, gunpowder, and other military supplies became more contentious, as the British sought to bring military stores more directly under their control, and the Patriot colonists sought to acquire them for their own use.
When the horrid news was brought here of the bombardment of Boston, which made us completely miserable for two days, we saw proofs of both the sympathy and the resolution of the continent. War! war! war! was the cry, and it was pronounced in a tone which would have done honor to the oratory of a Briton or a Roman. If it had proved true, you would have heard the thunder of an American Congress.”— John Adams, reporting on the reaction of the First Continental Congress in Philadelphia