The Powder Alarm occurs when news spreads that British troops are advancing toward militia stores of gunpowder in Somerville, Massachusetts. Patriots in the area, fearing an imminent attempt by British forces to disarm them, rapidly gather and prepare for confrontation. This response showcases the intense apprehensions amongst Massachusetts colonists towards British intentions. The dramatic mobilization sees militia units hastily assembling to protect their military supplies and community against perceived threats, signifying a turn toward active resistance against colonial governance. Local leaders, including members of the Sons of Liberty, play crucial roles in organizing these efforts, aiming to prevent any British incursion and asserting their rights in the face of British authority.

Although no shots are fired and no direct conflict occurs, the Powder Alarm exemplifies the existing tensions between colonists and British troops. The episode reflects escalating unrest, serving to unite various factions of colonial society against a common enemy. News spreads quickly throughout the region, resulting in towns preparing for potential conflict, thus mobilizing a larger segment of the population toward the cause of independence. This mass reaction to a perceived threat highlights the political awakening among the colonists and identifies the Powder Alarm as a precursor to deeper revolutionary actions leading up to the American Revolutionary War.