Powder Production

Black powder was made from charcoal, saltpeter, and sulfur, which reacted when ignited to produce expanding gases that propelled projectiles in firearms and artillery. Raw saltpeter from the limestone cave mining industry contained impurities that absorbed moisture and weakened gunpowder, so both saltpeter and sulfur had to be refined to make reliable powder. Saltpeter came from nearby Saltpeter Cave and, in larger amounts, Bone Cave in Van Buren County. On April 1, 1862, the Confederate congress created a Niter Bureau, and Isaac Munroe St. John, a civil engineer turned soldier, was chosen to lead the Confederate Niter and Mining Corps. Gunpowder manufacture began by mixing the ingredients in proportions of about 75% saltpeter, 15% charcoal, and 10% sulfur, with the mixture kept wet through all but the last step to reduce the risk of combustion. It was then ground under huge mill rollers into mill cake, cooled and hardened in a cooling magazine, broken into fragments and sorted by size, with larger grains used for artillery and smaller grains for shoulder arms and pistols. In the final drying stage, when the powder was most combustible, the finished high-quality gunpowder was weighed and packed for shipment by railroad across the Confederacy. Confederate officials expected the Niter Corps to meet demand and lessen dependence on foreign imports, and Colonel George W. Rains recalled that a powder mill at Manchester, urged forward by Mr. Whiteman of Nashville under Tennessee war contracts, had one set of rollers operating by the middle of October 1861 and a second being erected, and that a month later, using saltpeter and charcoal from the refinery at Nashville, it was producing 1500 pounds of gunpowder daily.

Tennessee · United States