The British Are Coming: The War for America, Lexington to Princeton, 1775-1777 (The Revolution Trilogy Book 1)

by Rick Atkinson

War could not be waged with an occasional smuggled windfall, yet not a single American powder mill existed when the rebellion began. Mills operating during the French war had fallen into disrepair or been converted to produce flour or snuff. Of particular concern was the shortage of saltpeter—potassium nitrate, typically collected from human and animal dung, and the only scarce ingredient in gunpowder. Identified as a strategic commodity in the medieval Book of Fires for the Burning of Enemies, saltpeter had been imported to Europe from India through Venice for centuries; imperial Britain bought almost two thousand tons a year. The saltpeter was kneaded with small portions of sulfur and charcoal, then pulverized, dusted, glazed, and dried to make gunpowder. Saltpeter recipes soon appeared in American newspapers and pamphlets for patriots willing to collect the “effluvia of animal bodies” from outhouses, barns, stables, tobacco yards, and pigeon coops, preferably “moistened from time to time with urine.” Massachusetts offered £14 per hundred pounds, triple the price paid by Britain for Indian saltpeter. “I am determined never to have saltpeter out of my mind,” John Adams declared in October. “It must be had.”