The author:

Thomas F Walter served from 1861 to 1865 in company A of the 91st Pennsylvania Infantry.

"The hour set for the denouement was known to us, so at daybreak, on the morning of July 30th, I started to be with the boys, and see and do what I might in the emergency. I found that Co. A and Co. F., I think, had been sort of crowded out of the breastworks, and were lying back a little distance, and something nearer the fated fort than the rest of the regiment. They were huddled together in what they called a bomb-proof. This was a hole dug out something like a cellar, and roofed with logs and earth. The cause of this was that the rebels, several days before, had set a battery of two mortars in a hole in the field back of their works opposite, and had been sending shells over occasionally, nearly the size of a man's head. When one of them would sink into the ground and explode, a cartload of dirt would go flying about, and they were most discomforting devils to hear, high over head, going flit, flit, flit, as they turned over and spit fire. When a piece of artillery banged at us, we knew about where to expect its missile [sic], but when one of those things were hurled on its curving way, there was an aggravating uncertainty about whom it was most likely to drop on. Our bomb-proof was much too frail for what was expected of it, but as no very serious mischief had been done us yet, the fellows had lost a good deal of their dread of the things. The 91st Regiment's position on the front line was close to the extreme right of the 5th Corps. Next to our brigade came the division of colored troops, attached to the 9th Corps.

Only a few minutes remained when I got to the company before the fort was to go up. The arrangements were being discussed, and I think no shrewd soldier among us approved of the colored troops making the initial charge or attack. It was not to be supposed that they could keep Lee's army divided or whip it, and capture Petersburg. We were willing the darkies should have their full share of the dangers and hardships of the war, but we wanted neither to fight ahead of them or support them. They had not much experience; our faith in them was weak, and we wanted their share of the service kept as distinct from ours as circumstances would allow.

[Grand Army Scout and Soldiers' Mail v.3 #50 p.1]
The mine was now to be exploded. The artilleryman stood to their guns in the redoubts along our line, but we of the infantry had not been ordered to fall in when the minute arrived that had been set for the firing of the train. There was some depression in the ground where we lay, so that we could not see well off in the vicinity of the entrance to the mine, although we had a good view of the parapet of the doomed forts from the top of our bomb-proof, where several of us lay to watch for results. We kept our eyes strained, but thirty or forty long minutes got away and a quietness almost oppressive still reigned. We marveled at the delay and were fearing the attempt had ended in an egregious failure, when there came a heavy thud, and immense masses of the rebel earthwork were hurled upward and tumbled over. Smaller fragments of various kind mounted higher in the air, and a cloud of dust nearly obscured the place as our artillery in the vicinity drove their shot into the enemy's works all along. A tornado of destruction struck the rebels with the suddenness of a flash. Scarcely a man of them had been astir; so the surprise was complete and demoralizing. Some of their pickets rushed into our lines, and their breastwork near the mine was abandoned. Again our eyes were strained, expecting to see our colored comrades go surging across the wreck of the redoubt. A long ten minutes passed away, our artillery slackened its fire, but no blue-clad infantry appeared in the gap. We looked at each other in wonder and dismay, for we felt that some infernal insubordination or incompetency was blasting a more than golden opportunity.

Not less than twenty minutes, though I feel sure a half hour or more had gone before the sound of musketry over there told us the charge had been made. Plenty of time had been given the foe to prepare a deadly reception for the attacking force. Again our artillery thundered at their line of works, and the fight went on under our very noses, as it were, and we, lying about taking it easy. We could not see fast how the contest was going, but in less than an hour the racket had ceased, and we knew that one more disaster to our cause had reached its consummation. We knew too, that as usual, the subalterns who endured the suffering, were not to blame. Reports of the whole affair were soon among us. We heard that the commands were sent over without definite instruction, and got mixed and disorganized in and about the "crater." It was said the enemy attacked them from three sides, and our artillery fired into them. Harassed and confused, they made but a slight resistance. Many were shot down where they stood or in trying to get back to our lines. Some were captured, and at once shot by their malignant foes. It was a sickening and villainous affair in nearly all its aspects; sickening in the butchery that took place; villainous in the neglect and stupidity of the high officers of our army, who could have easily made it a brilliant success.

Many dead and wounded lay between the lines, but covered by rebel guns; no one dare approach them as they fairly scorched beneath the fierce summer sun. Night came at last, and though the enemy was intensely vigilant, several of the wounded managed to roll or drag themselves to succor or safety. Another day came and still the wounded and dead sweltered in the sun. This made the bodies so foul that the odor became sickening to all in the vicinity. On the morning of the third day the rebels agreed to their burial, so, seeing a flag of truce flying up at the ruins, our captain asked me if I would walk over with him. I went. A detail from the 9th Corps had dug long, shallow trenches, and the horrible work of dragging the bodies--mangled, bloated, foul and wormy together was going on. Surely this was war in its most awful aspect, and a sight never to be forgotten. A few of the enemy stood upon their works as sort of unconcerned spectators of the progress of the interment. I believe it was a day or two after this, when the rest of the regiment having been withdrawn from the front line, we made another camp, in which we spent several weeks."
'Personal recollections and experiences of an obscure soldier'
*At the Battle of the Crater, Petersburg, Virginia,  30 July 1864:

"A Negro slave who had run away from Alabama some time ago, recognized his "young master" in the fight of Saturday at Petersburg, and throwing down his musket rushed to the young man an threw his arms around his neck, at the same time exclaiming.  "You haven't hurt my young massa."  Just at this time a cuss, not so mercifully disposed, fired at the Alabamian, but the ball instead of hitting the object aimed at, took effect in the body of the repentant slave who threw his arms of protection around his "young massa;" inflicting a severe wound upon`him.  Master and slave came safely off the field together, and the wound of the latter was properly attended."

An early newspaper clipping found in the book Black Southerners in the Confederate Armies
  --  J. H. Segars & Charles Kelly Barrow
Battle of the Crater