The Norfolk Railroad enters Petersburg through a ravine. In the attack upon the enemy's lines, on the 18th of June, the hollow was gained and held by Burnside's troops, their most advanced position being about four hundred feet from the Rebel line.
Lieutenant-Colonel Henry Pleasants, commanding the Forty-Eighth Pennsylvania Regiment, a practical miner, conceived the idea of excavating a tunnel under the Rebel works and exploding a mine. He submitted the plan to Burnside, who approved it. General Meade said it could not be done. Major Duane, of the Engineers, laughed at the idea. Other officers, of high rank, scouted the project. Colonel Pleasants was fully convinced of its practicability, and set his men to work.
He made application at head-quarters for a theodolite to make a triangulation of the distance, but was refused its use. He was obliged to send to Washington to obtain one. No facilities were granted him. He could neither obtain boards, lumber, or mining-picks. But his regiment, numbering four hundred men, were mostly miners, and he was confident of success. Work was accordingly commenced on the 25th of June, at noon. No wheelbarrows being provided, the men were obliged to make hand-barrows of cracker-boxes. But they were at home in the earth, and not easily discouraged by difficulties or want of proper tools to work with, and pushed forward the gallery, which was about four and a half feet high and the same in width, with great zeal. The earth brought out was covered with bushes, to conceal it from the Rebels, who by its fresh appearance might suspect where the mine was being sunk, as it was known throughout the army that mining operations had been commenced, and the Rebels had heard of it. The Richmond papers published the news, and it was heralded through the North.
At every discharge of the Rebel artillery there was danger of the caving in of the earth; but Pleasants' daring burrowers crept steadily forward, till the noise overhead, as well as previous measurements, convinced them that they were immediately under the Rebel works. The main gallery was five hundred and ten feet in length, beside which were two lateral galleries, one thirty-seven and the other thirty-eight feet in length.
A short distance from the entrance, inside of the Union fortifications, a vertical shaft was sunk, in which a fire was kept constantly burning, to produce ventilation. Eight magazines were placed in the lateral galleries, charged with four tons of powder, strongly tamped, and connected by fuses. The mine was completed on the 23d of July.
Grant planned an assault upon the Rebel line, independently of the explosion of the mine. He sent two divisions of the Second Corps, with two divisions of Sheridan's cavalry, to the Army of the James, at Deep Bottom, where an attack was made, four guns captured, and the line extended from Deep Bottom to the New Market road. Lee attempted to recover his lost ground, but failed. Grant, in this expedition, employed an immense train of empty baggage-wagons, which, passing in sight of the Rebel pickets, made the movement an enigma to Lee. The Rebels in the fortifications had commenced a counter-mine, but suspended labor.
General Burnside wished that the colored troops of his division, under General Ferrero, should lead in the assault after the mine was exploded; and the troops were drilled with that special object in view. He believed that they would make a successful charge. They were fresh, had taken but little part in the campaign, and were desirous of emulating the example of their comrades of the Eighteenth Corps. The white troops were worn with hard marching, fighting, and exposure in the trenches in front of Petersburg, where they had been on the watch day and night. The lines were so near to the Rebels that a man could not show his head above the parapet without being shot. They had acquired the habit of taking their positions by covered approaches, and had lost the resolute confidence and fearlessness manifested at the beginning of the campaigns.
General Meade objected to Burnside's plan.
"I objected," says Meade, "not that I had any reason to believe that the colored troops would not do their duty as well as the white troops, but that they were a new division, and had never been under fire, had never been tried, and, as this was an operation which I knew beforehand was one requiring the very best troops, I thought it impolitic to trust to a division of whose reliability we had no evidence."[68]
The matter was referred to General Grant, who says:—