I Have Accomplished One of the Great Things of This War

During the lull in the fighting after the Second Petersburg Offensive, the 48th Pennsylvania began building a mine shaft ending underneath a major Confederate fort. The Pennsylvanians completed their tunnel in late July and packed it with 8,000 pounds of black powder. This chapter describes the details behind this, the most famous engineering accomplishment of the entire campaign, and Confederate efforts to verify its existence and location. The Union Ninth Corps designated its African American division to lead any attack that would follow the mine’s detonation, although there remains some doubt as to the amount of training these men received for their unique assignment. General Grant’s plans for his Third Petersburg Offensive, however, relied not on the mine, but on a movement north of the James River targeting Richmond and its supply lines to the north and west. The conduct of that operation, called First Deep Bottom, failed to achieve its goals between July 26th and 28th. However, it succeeded in drawing much of Lee’s army away from Petersburg, elevating the mine’s potential importance.