in preparation for the ten-month siege that followed. On June 19, Ferrero's (4th) Division of black troops rejoined the corps, having been absent during the whole of the previous campaign, engaged on duty at the rear. Ferrero's men were now placed in the trenches with the other three divisions. The part of the line occupied by the IX Corps was very near the enemy's works, and an incessant firing was kept up during the siege, resulting in a daily loss of men, killed or wounded. While there was a comparative quiet in front of the other corps positions, the men of the IX Corps were subjected to the terrible strain of a constant watchfulness and deadly exposure. The enemy seemed to be excited to an undue activity by the presence of Ferrero's Colored Division. The IX Corps was prominently connected with the siege because of its role in the infamous Battle of the Crater, in which a lengthy mine shaft was dug from its line to under the Confederate works. This mine, which was excavated by the coal miners of 48th Pennsylvania, Potter's Division, was successfully exploded with four tons of gunpowder, resulting in an enormous crater, but the assault that followed was a failure. Just before the assault, Grant and Meade directed Burnside to replace Ferrero's black division with Ledlie's white division, fearful of the political consequences of using black troops at the forefront of a major assault. But Ledlie's troops were not trained for the assault and Ledlie himself remained in the rear area, inebriated. The assault was a fiasco, in which Union soldiers charged into the crater, becoming trapped there, easy targets for the Confederates along the crater's rim. Ferrero's black regiments went into action in the rear and fought well, but had no chance for success. The losses in the IX Corps at the crater were 473 killed, 1,646 wounded, 1,356 missing; total, 3,475. Immediately after this engagement, General Ledlie was relieved from command of the 1st Division, and Brig. Gen. Julius White, of the XXIII Corps, was assigned to Ledlie's place. On August 13, 1864, General Burnside was granted a leave of absence; he never rejoined the corps, but was succeeded by General Parke, who remained in command until the close of the war. At the battle of the Weldon Railroad, August 19–21, 1864, the three divisions of White, Potter, and Willcox were engaged with