The gallery to the mine was over five hundred feet long from where it entered the ground to the point where it was under the enemy’s works, and with a cross gallery of something over eighty feet running under their lines.  Eight chambers had been left, requiring a ton of powder each to charge them.  All was ready by the time I had prescribed; and on the 29th Hancock and Sheridan were brought back near the James River with their troops.  Under cover of night they started to recross the bridge at Deep Bottom, and to march directly for that part of our lines in front of the mine.

Warren was to hold his line of intrenchments with a sufficient number of men and concentrate the balance on the right next to Burnside’s corps, while Ord, now commanding the 18th corps, temporarily under Meade, was to form in the rear of Burnside to support him when he went in.  All were to clear off the parapets and the abatis in their front so as to leave the space as open as possible, and be able to charge the moment the mine had been sprung and Burnside had taken possession.  Burnside’s corps was not to stop in the crater at all but push on to the top of the hill, supported on the right and left by Ord’s and Warren’s corps.

Warren and Ord fulfilled their instructions perfectly so far as making ready was concerned.  Burnside seemed to have paid no attention whatever to the instructions, and left all the obstruction in his own front for his troops to get over in the best way they could.  The four divisions of his corps were commanded by Generals Potter, Willcox, Ledlie and Ferrero.  The last was a colored division; and Burnside selected it to make the assault.  Meade interfered with this.  Burnside then took Ledlie’s division—­a worse selection than the first could have been.  In fact, Potter and Willcox were the only division commanders Burnside had who were equal to the occasion.  Ledlie besides being otherwise inefficient, proved also to possess disqualification less common among soldiers.

There was some delay about the explosion of the mine so that it did not go off until about five o’clock in the morning.  When it did explode it was very successful, making a crater twenty feet deep and something like a hundred feet in length.  Instantly one hundred and ten cannon and fifty mortars, which had been placed in the most commanding positions covering the ground to the right and left of where the troops were to enter the enemy’s lines, commenced playing.  Ledlie’s division marched into the crater immediately on the explosion, but most of the men stopped there in the absence of any one to give directions; their commander having found some safe retreat to get into before they started.  There was some delay on the left and right in advancing, but some of the troops did get in and turn to the right and left, carrying the rifle-pits as I expected they would do.