Edward Porter Alexander, Military memoirs of a Confederate: a critical narrative

The explosion made a crater 150 feet long, 97 feet wide, and 30 feet deep, the contents being hurled so high in the air that the foremost ranks of the assaulting columns, 150 yards away, shrank back in disorder in fear of the falling earth. The bulk of the earth, however, fell immediately around the crater, mingled with the debris of 2 guns, 22 cannoneers, and perhaps 250 infantry (nine companies of the 19th and 22d S. C., which had been carried up in the air). Quite a number of these who fell safely were dug out and rescued alive by the assaulting column. Some, not yet aroused, were lost, covered up in the bomb-proofs of the adjacent trenches by the falling earth. This formed a high embankment, as it were, all around the crater, with one enormous clod, the size of a small cabin, perched about the middle of the inside rim, which remained a landmark for weeks. A high interior line, called a trench cavalier, had been built across the gorge of the salient enclosing a triangular space, and the left centre of this space about coincided with the centre of the explosion. The parapets were partially destroyed and largely buried by the falling earth.

Into this crater the leading division literally swarmed, until it was packed about as full as it could hold, and what could not get in there, crowded into the adjacent trenches, which the falling earth had caused to be vacated for a short distance on each flank. But, considering the surprise, the novelty of the occasion and the terrific cannonade by 150 guns and mortars which was opened immediately, the coolness and self-possession of the entire brigade was remarkable, and to it is to be attributed the success of the defence. This was conducted principally by Col. McMaster of the 17th S. C., Gen. Elliott having been soon severely wounded. The effect of the artillery cannonade was more a moral effect than a physical one, for the smoke so obscured the view that the fire was largely at random, at least for one or two hours, during which it was in fullest force. The effort was at once made to collect a small force in the trenches upon each flank, and one in an intrenchment occupying a slight depression which ran parallel to our line of battle some 250 yards in rear