Two armies were facing each other outside a small city. They had been at grips for 50 days and the struggle had taken them over 70 miles of ground, finally to this point. Four days of attack the week before had brought the troops to the very edge of the city, which was the key to the belligerent capital; but there the assaults had worn themselves out, and hastily built entrenchments and batteries blocked the way.

At one place along the three-mile line the attackers had seized the edge of a hill and entrenehed themselves at nightfall within shouting distance of a defensive battery. Holding that section of advanced line were 400 men of a regiment recruited in the coal mining country. They probably were not too much interested in the strategic situation, but they did want to advance, or at least to do something more entertaining than dodging bullets in the heat and confinement of the trenches. Directly in front was a Confederate battery, 135 yards from the Union trench. That was the key to Petersburg, and there the 48th Pennsylvania Regiment intended to go. No men could live to reach that battery above ground; but it appeared to be feasible to tunnel under it.

(click to see a copy of the original page for this article)

The colonel, Henry Pleasants, a mining engineer, pursued the idea through proper military channels.¹ Some of his superiors favored it; some scoffed.² Others were indifferent but admitted it could do no harm, and would keep the men amused.³ Colonel Pleasants gathered such necessary materials as he could find while the digging progressed, using every possible makeshift to obtain what he needed with or without official support.⁴

The operation involved was, of course, not a new expedient in war, but the necessary unbroken length of tunnel was greater than had ever been attempted. Colonel Delafield of the Engineers had duly reported the digging of 1,251 running meters of gallery, some of it 50 feet underground, by the French in the Crimea.⁵ A rumor reached Confederate headquarters that mining was under way, but an Englishman visiting there stated that at the siege of Delhi it had proved impossible to run a tunnel more than 400 feet.⁶ At Vicksburg the year before there had been a Federal mine, but the tunnel was started from an approach trench which had already reached the defenders' ditch. Twelve hundred pounds of powder were used. Since the Confederates knew fairly well what was going on, although countermining failed, they lost few men in the explosion and, having previously constructed a second line, held the remainder of the fort without difficulty. Two Union regiments occupied the breach, losing about 30 men.⁷

There was, then, a recent precedent for Colonel Pleasants' project, a precedent of which Grant had full knowledge. The Petersburg mine, however, was on a much larger scale, and every effort was made to keep knowledge of it from the Confederates. So far as the exact location was concerned this was accomplished. The excavated earth was scattered along parapets or covered with brush before daylight.⁸ Nevertheless the enemy heard something of a mining operation and began to dig, early in July, at several likely points --- including Pegram's battery, the objective of Pleasants' tunnel.⁹

The Pennsylvanians were having their troubles.¹⁰ Army picks had to be reshaped for use underground. Planking came from an old bridge, and later from a sawmill five miles away. The tunnel collapsed when it reached a wet spot and had to be retimbered. A putty-like marl slowed the digging which, as the tunnel lengthened, required the work of all 400 men in the regiment. It had been stated by various authorities that bad air would stop the work. To avoid this a ventilation system was devised. It consisted of a wooden tube leading from the entrance to the end of the tunnel, and a chimney just behind the Union works. A fire in that chimney caused a draft through the tunnel. As the smoke had to be concealed, fires were kept burning at intervals along the line as though the men were cooking. It was necessary to keep a check on the length and direction of the tunnel. For this purpose, using a crude transit (the only one he had been able to obtain), Pleasants made observations from the front line, within 130 yards of the Confederate sharpshooters. By this risky and hurried expedient he was able to place the mine exactly, as events proved.¹¹

Occupied with these labors, Colonel Pleasants was no doubt glad to receive a letter from Brigadier General J. G. Barnard, Chief Engineer of the Armies in the Field, dated City Point, July 3, containing 10 detailed questions concerning his progress and plans. Pleasants replied four days later, answering three of the queries,¹² It appears that this was the only official interest shown in the actual process, although there was much discussion about its possible results and the best method of utilizing them.

HUMOR AT THE FRONT The tragedies of war almost invariably are tempered by the good natured jests of the soldier. Confederates in the ranks accepted the rumors of a Federal mine as something of a joke and told newcomers that Grant's men were attempting to tunnel all the way under Petersburg and attack the Southern army from the rear. Conscripts were informed solemnly by the more seasoned Veterans that the mine already had reached Sycamore Street, the main thoroughfare of the town, and that a railroad was being operated in it. Greenhorns were assured that by listening carefully they could hear the roar of the locomotive, and that smoke could be seen issuing from the spaces between the cobblestones in the street. ---Adapted from Douglas Southall Freeman, R. E. Lee: A Biography (Charles Scribner's Sons, New York, 1936), III, 464.

The Confederates had dug a shaft and horizontal listening gallery on each side of Pegram's Battery, where their tunneling reached a total length of 203 feet. These shafts were only 10 feet under the ground while the Federals were 20 feet under, so that the Confederates apparently could not hear their enemy,¹³ although their digging was audible to the Federals and caused a cessation of work for one day. Curiously enough, the Confederate miners at Colquitt's Salient, a mile distant, reported that they heard Federal digging, although none appears to have been in progress at that point.¹⁴

Pleasants' men continued their work on July 18, digging a gallery 75 feet long across the end of the 510-foot main tunnel and following the assumed course of the Confederate works. This was finished July 23, but the explosive was not put in place immediately. Eight thousand pounds of powder were used for the charging, and all was complete on July 28 save for lighting the fuze.¹⁵ Unfortunately, the fuze was supplied in short lengths that had to be spliced. Half an hour after it was lighted at 3:30 a. m., July 30, there was no result. Two men of the 48th volunteered to relight it. Then, at 4:44, in the first light of day, Pegram's Battery, with 278 men and four guns, was demolished and hurled into the air. "The size of the crater formed by the explosion was at least 200 feet long, 50 feet wide, and 25 feet deep."¹⁶

The miner had done his work, and done it well. It now was up to the infantry.¹⁷