The Battle of the Crater was a battle of the American Civil War which was fought amid the Siege of Petersburg in 1864.
Remembering the bloody failure of his frontal attacks against entrenched Confederate positions at the Battle of Cold Harbor, Union general Ulysses S. Grant refused to attack the strong Confederate defenses of Petersburg in a similar manner. Lieutenant-Colonel Henry Pleasants of the 48th Pennsylvania Infantry Regiment proposed having the Pennsylvania miners of his unit dig a mine shaft underneath the Confederate lines and plant explosive charges beneath Elliott's Salient, which would kill al of the defenders in the area and open a gap in the Confederate line, through which the Union forces could break through. Pleasants' commanding officer, Major-General Ambrose Burnside, agreed to the plan, although Grant and General George Meade did not take the plan seriously and neglected to provide it with adequate resources.
On 17 July, the main shaft reached under the Confederate position, and, while General Robert E. Lee received reports of Union mining attempts, he did not attempt to act on countering them until two weeks later, and Confederate counter-mining efforts failed to locate the Union tunnel. Three days after the failed First Battle of Deep Bottom, Grant and Meade finally decided to use the mine, and General Edward Ferrero's division of United States Colored Troops (USCT) - consisting of Joshua K. Sigfried's 1st Brigade (27th, 30th, 39th, and 43rd USCT) and Henry Goddard Thomas' 2nd Brigade (the 19th, 23rd, 28th, 29th, and 31st USCT) - was assigned to lead the assault. Burnside's other two (white) divisions would would support Ferrero's flanks and make a move against Petersburg itself in conjunction with the assault. Meade attempted to dissuade Burnside from using Black troops as the vanguard, fearing their needless slaughter by the white supremacist Confederates if the assault went awry, and perhaps also doubting their combat abilities. Grant concurred with Meade, and James H. Ledlie's division was assigned to head the assault.
At 4:44 AM on 30 July 1864, the charges exploded, vaporizing 278 Confederate soldiers of the 18th and 22nd South Carolina Infantry Regiments, unleashing a shower of earth, men, and guns onto the surviving Confederate soldiers, and creating a 30-foot-deep blast crater. However, the drunken Ledlie neglected to order an immediate assault, and the Union soldiers waited ten minutes before attacking. His troops also foolishly decided that the Crater would make an excellent rifle pit, rather than moving around it to press the attack, and the deep pit soon became an overcrowded death trap as Confederate soldiers partook in a "turkey shoot" of the trapped Union soldiers. Rather than cut his losses, Burnside sent in Ferrero's Black division, and the Union soldiers, who lacked ladders, were forced to climb to survival or be massacred by either rifle fire or in melee combat. The vast majority of the Union losses in the Crater were Black soldiers, as the racist rancor shown by the Confederate enlisted men led to a slaughter of the USCT men. Only the intervention of Confederate general William Mahone prevented the murder of the captured USCT soldiers. Grant lamented the loss of the unique opportunity to blast a way into Petersburg, and Burnside was permanently relieved of command due to the failure of the attack.