1777 dated Revolutionary War Document for Salt Petre - Salt Petre was used to make Gun Powder - American Revolutionary War

Handwritten pay authorization for "purchase and premium" of Salt Petre.

Saltpetre, or potassium nitrate, has historically played a pivotal role in both food preservation and military technology. It served as a crucial ingredient in gunpowder and was used as a meat curing agent. Initially harvested from cave dirt, bat guano, or decomposed organic matter in stables, this “salt of rock” was essential for early chemical industries.

During the American Civil War, the demand for saltpetre surged, leading to extensive mining in Appalachian caves. Laborers known as “peter monkeys” extracted the compound for the Confederacy. Initially used as a preservative, its role shifted towards industrial manufacturing after large deposits of sodium nitrate were discovered in Chile in the 1850s. This discovery eventually transformed the production of ammunition and fertilizers.