General Ledlie's division of white troops was to lead the assault, after the explosion of the mine on the morning of the 30th. It was on the night of the 29th, when General Burnside issued his battle order, in accordance with General Meade's plan and instructions, and at the appointed hour all the troops were in readiness for the conflict. The mine, with its several tons of powder, was ready at a quarter past three o'clock on the eventful morning of the 30th of July. The fuses were fired, and "all eyes were turned to the confederate fort opposite," which was discernible but three hundred feet distant. The garrison was sleeping in fancied security; the sentinels slowly paced their rounds, without a suspicion of the crust which lay between them and the awful chasm below. Our own troops, lying upon their arms in unbroken silence, or with an occasional murmur, stilled at once by the whispered word of command, looked for the eventful moment of attack to arrive. A quarter of an hour passed,—a half hour, yet there was no report. Four o'clock, and the sky began to brighten in the east; the confederate garrison was bestirring itself. The enemy's lines once more assumed the appearance of life; the sharpshooters, prepared for their victims, began to pick off those of our men, who came within range of their deadly aim. Another day of siege was drawing on, and still there was no explosion. What could it mean? The fuses had failed;—the dampness having penetrated to the place where the parts had been spliced together, prevented the powder from burning. Two men (Lieut. Jacob Douty and Sergeant—afterwards Lieutenant—Henry Rees,) of the 48th Pennsylvania volunteered to go and ascertain where the trouble was. At quarter past four o'clock they bravely entered the mine, re-arranged the fuses and relighted them. In the meantime, General Meade had arrived at the permanent headquarters of the 9th Corps. Not being able to see anything that was going forward, and not hearing any report, he became somewhat impatient. At fifteen minutes past four o'clock he telegraphed to General Burnside to know what was the cause of the delay. Gen. Burnside was too busy in remedying the failure already incurred to reply immediately, and expected, indeed, that before a dispatch could be sent that the explosion would take place. General Meade ill-naturedly telegraphed the operator to know where General Burnside was. At half-past four, the commanding general became still more impatient, and was on the point of ordering an immediate assault upon the enemy's works, without reference to the mine. Five minutes later he did order an assault. General Grant was there when, at sixteen minutes before five o'clock, the mine exploded. Then ensued a scene which beggars description.
General Badeau, in describing the spectacle, says:
"The mine exploded with a shock like that of an earthquake, tearing up the rebels' work above them, and vomiting men, guns and caissons two hundred feet into the air. The tremendous mass appeared for a moment to hang suspended in the heavens like a huge, inverted cone, the exploding powder still flashing out here and there, while limbs and bodies of mutilated men, and fragments of cannon and wood-work could be seen, then all fell heavily to the ground again, with a second report like thunder. When the smoke and dust had cleared away, only an enormous crater, thirty feet deep, sixty wide, and a hundred and fifty long stretched out in front of the Ninth Corps, where the rebel fort had been."
The explosion was the signal for the federal batteries to open fire, and immediately one hundred and ten guns and fifty mortars opened along the Union front, lending to the sublime horror of the upheaved and quaking earth, the terror of destruction.
A confederate soldier thus describes the explosion, in the Philadelphia Times, January, 1883:
"About fifteen feet of dirt intervened between the sleeping soldiers and all this powder. In a moment the superincumbent earth, for a space forty by eighty feet, was hurled upward, carrying with it the artillery-men, with their four guns, and three companies of soldiers. As the huge mass fell backwards it buried the startled men under immense clods—tons of dirt. Some of the artillery was thrown forty yards towards the enemy's line. The clay subsoil was broken and piled in large pieces, often several yards in diameter, which afterwards protected scores of Federals when surrounded in the crater. The early hour, the unexpected explosion, the concentrated fire of the enemy's batteries, startled and wrought confusion among brave men accustomed to battle."
Says a Union account:
"Now was the time for action, forward went General Ledlie's column, with Colonel Marshall's brigade in advance. The parapets were surmounted, the abatis was quickly removed, and the division prepared to pass over the intervening ground, and charge through the still smoking ruins to gain the crest beyond. But here the leading brigade made a temporary halt; it was said at the time our men suspected a counter mine, and were themselves shocked by the terrible scene they had witnessed. It was, however, but momentary; in less than a quarter of an hour, the entire division was out of its entrenchments, and was advancing gallantly towards the enemy's line. The ground was somewhat difficult to cross over, but the troops pushed steadily on with soldiery bearing, overcoming all the obstacles before them. They reached the edge of the crater, passed down into the chasm and attempted to make their way through the yielding sand, the broken clay, and the masses of rubbish that were everywhere about. Many of the enemy's men were lying among the ruins, half buried, and vainly trying to free themselves. They called for mercy and for help. The soldiers stopped to take prisoners, to dig out guns and other material. Their division commander was not with them, there was no responsible head, the ranks were broken, the regimental organizations could not be preserved, and the troops were becoming confused. The enemy was recovering from his surprise, our artillery began to receive a spirited response, the enemy's men went back to their guns; they gathered on the crest and soon brought to bear upon our troops a fire in front from the Cemetery Hill, and an enfilading and cross-fire from their guns in battery. Our own guns could not altogether silence or overcome this fire in flank, our men in the crater were checked, felt the enemy's fire, sought cover, began to entrench. The day was lost, still heroic men continued to push forward for the crest, but in passing through the crater few got beyond it. Regiment after regiment, brigade followed brigade, until the three white divisions filled the opening and choked the passage to all. What was a few moments ago organization and order, was now a disordered mass of armed men. At six o'clock, General Meade ordered General Burnside to push 'his men forward, at all hazards, white and black.' His white troops were all in the crater, and could not get out. As instructed, he ordered General Ferrero to rush in the Phalanx; Colonel Loving was near when the order came to Ferrero; as the senior staff officer present, seeing the impossibility of the troops to get through the crater, at that time countermanded the order, and reported in person to General Burnside, but he had no discretion to exercise, his duty was simply to repeat Meade's order. The order must be obeyed; it was repeated; away went the Phalanx division, loudly cheering, but to what purpose did they advance? The historian of that valiant corps, presumably more reliable than any other writer, says:
"'The colored troops charged forward, cheering with enthusiasm and gallantry. Colonel J. K. Sigfried, commanding the first brigade, led the attacking column. The command moved out in rear of Colonel Humphrey's brigade of the Third Division. Colonel Sigfried, passing Colonel Humphrey by the flank, crossed the field immediately in front, went down the crater, and attempted to go through. The passage was exceedingly difficult, but after great exertions the brigade made its way through the crowded masses in a somewhat broken and disorganized condition, and advanced towards the crest. The 43rd U. S. Colored troops moved over the lip of the crater toward the right, made an attack upon the enemy's line of intrenchments, and won the chief success of the day, capturing a number of prisoners and rebel colors, and re-capturing a stand of national colors. The other regiments of the brigade were unable to get up, on account of white troops in advance of them crowding the line. The second brigade, under command of Colonel H. G. Thomas, followed the first with equal enthusiasm. The men rushed forward, descended into the crater, and attempted to pass through. Colonel Thomas' intention was to go to the right and attack the enemy's rifle-pits. He partially succeeded in doing so, but his brigade was much broken up when it came under the enemy's fire. The gallant brigade commander endeavored, in person, to rally his command, and at last formed a storming column, of portions of the 29th, 28th, 23rd, and 19th Regiments of the Phalanx division.'
"'These troops' made a spirited attack, but lost heavily in officers and became somewhat disheartened. Lieutenant-Colonel Bross, of the 29th, with the colors in his hands, led the charge; was the first man to leap upon the enemy's works, and was instantly killed. Lieutenant Pennell seized the colors, but was shot down, riddled through and through. Major Theodore H. Rockwood, of the 19th, sprang upon the parapet, and fell while cheering on his regiment to the attack. The conduct of these officers and their associates was indeed magnificent. No troops were ever better lead to an assault; had they been allowed the advance at the outset, before the enemy had recovered from his first surprise, their charge would have been successful. But it was made too late. The fire to which they were exposed was very hot and destructive; it came from front and flank, it poured into the faces of the men. It enfiladed their lines. The enemy's rage against the colored troops had its bloody opportunity."