Virginia's Mineral Resources and the American Civil War
Niter is the mineral form of potassium nitrate, KNO3, also known as saltpeter, commonly found as massive encrustations and effervescent growths on cave walls, ceilings, and floors. Along with sulfur and charcoal, niter is an essential ingredient in gunpowder.
Virginia caves are known to have been worked for saltpeter as early as 1740 (Faust, 1964) and they supplied niter for gunpowder during the American Revolution and the War of 1812. Production figures are almost non-existent, although the 1810 U.S. Census did report that Virginia provided 59,175 pounds of saltpeter that year. During the ensuing decade, consumption increased drastically due to frontier fighting, subsistence hunting, government military requirements, and the use of explosives in mining and construction of roads and canals (Faust, 1964). Apparently the increased demand was not matched by domestic production, as Virginia, along with the rest of the Southern states, imported most of their gunpowder in the years leading up to the Civil War.
In 1862, as the Federal naval blockade began to curtail foreign imports, the Confederate Government set up the Nitre Corps, which soon expanded into the Nitre and Mining Bureau. One of the bureau’s principle missions was to find and develop nitrate caves. It has been estimated that twenty-five caves in Virginia produced saltpeter during the war (Powers, 1981), among them Buchanan Saltpeter Cave in Smyth County, Perry’s Saltpeter Cave near Eagle Rock, Repass Cave near Bland, Trout Cave near Franklin (now in West Virginia), probably Sinnet Cave south of Franklin, and most likely Clark’s Saltpeter Cave — one of the longest-producing caves in the region — near Fort Lewis. The majority of operations were small, but by using basic procedures three men could produce 100 to 200 pounds of saltpeter in three days (Powers, 1981). Records of mining activities are scarce and it is not unusual for the names of caves to change. In addition, this was largely a cottage industry — the caves were usually worked by mountain folk from small farms with no slaves and who were only marginally loyal to the Confederacy, resulting in “a notoriously unreliable work force where absenteeism and desertion were common” (Whisonant, 2001).
Saltpeter operations were widely scattered and difficult to locate, so they were not principal military targets, although they were occasionally assaulted by Federal raiders. General William Averell, on his way to tear up the Virginia & Tennessee Railroad in December 1863, disrupted the mining operations near Mountain Grove in Bath County. During the first week in March 1864, the 12th New York Cavalry destroyed the saltpeter works above Franklin, and the captured miners were taken to a prisoner-of-war camp at Old High Town above Monterey (Morton, 1910). The battles at Saltville in October and December 1864 temporarily suspended saltpeter operations at nearby Buchanan Cave. Nevertheless, during most of the war Confederate niter production kept pace with the growing demands of the military (Whisonant, 2001). Records from the Nitre and Mining Bureau reported that through 1864 Virginia produced 505,584¼ pounds of niter, accounting for about 29% of the total Confederate domestic supply (Schroeder-Lein, 1993).
After the war, cheap saltpeter produced from Chilean bird guano deposits began to flood the international markets, and the demand for domestic production disappeared. Then, around 1909, German scientist Fritz Haber developed a method for producing nitrates in the laboratory, relegating natural sources to the past.
Faust, Burton, 1964, Saltpetre caves and Virginia history, in Douglas, Henry H., Caves of Virginia: Econo Print, Falls Church, Virginia.
Morton, Oren, 1910, A history of Pendleton County, West Virginia: Franklin, West Virginia.
Powers, J., 1981, Confederate niter production: National Speleological Society, Bulletin, v. 43.
Schroeder-Lein, G. R., 1993, Niter and Mining Bureau, in Current., R.N., editor, Encyclopedia of the Confederacy: Simon and Schuster, New York.
Whisonant, Robert C., 2001, Geology and history of Confederate saltpeter cave operations in western Virginia: Virginia Minerals, v. 47, no. 4.