During the Siege of Petersburg in 1864, Lieutenant Colonel Henry Pleasants, a Pennsylvania mining engineer leading the 48th Pennsylvania and its former coal miners, proposed tunneling under Elliott’s Salient in the Confederate line. Grant and Meade saw it as busy work and denied supplies, so the men tore down a bridge and a sawmill for timber and hauled dirt in modified cracker boxes. Pleasants ventilated the 511-foot shaft with a fire-driven exhaust and a wooden duct, dipped beneath Confederate countermines, and packed the T-shaped end with 320 kegs, about 8,000 pounds, of powder. Ambrose Burnside trained a United States Colored Troops division under Edward Ferrero to lead the assault.

The day before the attack, Meade, backed by Grant, barred the USCT division from leading, and Burnside had three white commanders draw lots; James H. Ledlie won. On July 30 the fuse failed, two volunteers relit it, and at 4:44 a.m. the blast killed 278 Confederates and left a crater about 170 feet long and 30 feet deep. Untrained troops poured into the pit, William Mahone’s men surrounded the rim, and the Union lost nearly 3,800 men to about 1,500 Confederate casualties. Burnside was relieved, Ledlie and Ferrero were dismissed, and the siege went on for eight more months.

• Lieutenant Jacob Douty and Sergeant Harry Reese crawled into the dark tunnel to splice and relight the failed fuse.
• Union troops lost about ten minutes climbing over their own parapets because no footbridges had been prepared.
• Ledlie and Ferrero were reported to be sharing rum in a bombproof behind the lines during the fighting.
• Native American soldiers of the 1st Michigan Sharpshooters sang death songs as they were overrun near the earthworks.
• USCT casualties ran close to one killed for every wounded man, amid documented killings of Black soldiers trying to surrender.