"We could blow that damn fort out of existence if we could run a mine shaft under it."
- A private of the 48th Pennsylvania June 23, 1864
Spurred by the offhand suggestion of a former coal miner, on June 25, 1864, Lieutenant Colonel Henry Pleasants put his 48th Pennsylvania to digging. Their objective: to tunnel under the Confederate line and low up the battery at Elliott's Salient.
Beginning on June 25, 1864, and continuing for the next month, these Pennsylvania coal miners burrowed a shaft 511 feet into this hillside. Then they packed four tons of powder into the magazines under the Confederate battery. At 3:15 a.m. on July 30, Pleasants lit the fuse and scrambled out of the tunnel.