This is an account of an operation which could have ended the Civil War 9 months earlier and it fills in -- with detail -- the circumstances, events and aftermath of the climax on July 30, 1864. The Army of the Potomac, blocked by Petersburg's fortifications, included the 48th Pennsylvania Regiment of Volunteers, which was composed of anthracite coal miners, and Lt. Col. Henry Pleasants (a cousin of the author) was not only one of its officers but a mining engineer. A remark sparked him to go to Burnside and suggest digging a tunnel that would run under the fort which then could be dynamited. And, in spite of every kind of obstruction in which lack of top rank sanction, of assistance in providing necessary tools and equipment, this was done -- a mine of 511 feet, with lateral galleries of 75 feet, was dug by 400 men in four weeks, in view of, and under fire from, the enemy. The fort was blown up but the following attack was a bloody disaster for the Union troops were failed by their officers as well as by weak coordination of all efforts, shown by future investigations. This is young Pleasants' story and a tribute to an almost impossible assignment; it is also the story of the interplay of Meade and Burnside, of Grant's ignorance of the whole situation, of the shifting of plans and the temper of the Army. It should be a special footnote to an unexploited episode for all that has gone before in Civil War data finding.