Page "Battle of the Crater" Paragraph 4

Pleasants, a mining engineer from Pennsylvania in civilian life, proposed digging a long mine shaft underneath the Confederate lines and planting explosive charges directly underneath a fort ( Elliott's Salient ) in the middle of the Confederate First Corps line.

If successful, this would not only kill all the defenders in the area, it would also open a hole in the Confederate defenses.

If enough Union troops filled the breach quickly enough and drove into the Confederate rear area, the Confederates would not be able to muster enough force to drive them out, and Petersburg might fall.

Burnside, whose reputation had suffered from his 1862 defeat at the Battle of Fredericksburg and his poor performance earlier that year at the Battle of Spotsylvania Court House, gave Pleasants the go-ahead.