sentences:  Page 85 of the February 6, 1864 issue of Harper's Weekly shows a drawing of the cave entrance and some of the saltpeter mining and refining equipment located outside the cave.Robert Cravens, a Chattanooga businessman, operated Nickajack Cave and his own cave, Lookout Mountain Cave at the beginning of the Civil War.Soon after the war started, the operation at Nickajack Cave was taken over by the Confederate government.