The Battle of the Crater saw the failure of one of the more imaginative Union attempts to break through the Confederate lines defending Petersburg. Grant had moved his army south of the James River in mid-June, hoping to capture Petersburg or at least block the railroad lines into the city before Lee could respond. A series of half-hearted attacks combined with some skilful defence on the part of General Beauregard had foiled that plan (Battle of Petersburg, 15-18 June), and Grant’s men had settled into their trenches, ready for a long siege.
One of his officers thought they had the answer to this deadlock. Colonel Henry Pleasants, commander of the 48th Pennsylvania Regiment, had been a mining engineer before the war. Many of his men were also ex-miners. Their section of the Union line came within 150 yards of a Confederate fort, and between them they came up with a plan to destroy that fort by exploding a mine underneath it.
This would require them to build a tunnel 500 feet long. For a nineteenth century coal miner this was hardly a challenge – tunnels four times this length could be found in the Pennsylvania mines. However, military engineers had never constructed a tunnel of this length. Of course they did operate under some disadvantages compare to the miners – they didn’t have the same amount of time, nor could they build the impressive mine-head buildings that were common at most deep mines. Secrecy was crucial to any such tunnelling operation, so major building works would be an obvious giveaway.
The army engineers refused to get involved in what they regarded as a pointless waste of effort. This may well have helped the miners, allowing them to get on with their project uninterrupted. They had the support of their corps commander, General Burnside, who was more willing than most to listen to unusual ideas. By the end of June they had built their 500 foot tunnel, as well as 40 feet of tunnels underneath the Confederate lines, which were filled with gunpowder. Confederate counter-mining efforts failed to locate this tunnel – their own engineers were just as convinced that no such tunnel was possible.
With the tunnel approaching success, preparation began above ground for a possible assault. Burnside selected his largest and freshest division, his Fourth Division, for the attack. His other three divisions had been in combat since the Wilderness, and were in no fit state to launch another attack. The only problem was that this division contained black troops. In something of a catch-twenty two situation, the Fourth Division had been denied combat because it had no combat experience. Now they were to get their great chance. They were as keen as any unit in the Union army, determined to prove their fighting ability.
Right at the last minute they were denied that chance. Despite eleven days of intense training, on 29 July General Meade decided to withdraw them from the operation. There appears to have been a combination of reasons for this. First was the concern about using an inexperienced division, especially on such a complex operation. Second was a general worry about the consequences of using a black division in such an attack. If things went wrong, Grant and Meade could have been accused of using their black soldiers in an unjustifiably risky attack.
Burnside now demonstrated one of his weaknesses. He appears to have lost all interest in the attack. Rather than pick his second freshest division, or best led division, or using any other rational means to choose who was to attack, Burnside decided to draw straws! The ‘winner’ was Brigadier General James H. Ledlie. His was probably Burnside’s weakest division, and he was certainly the worst of the commanders. On 30 July Ledlie decided to command from the vicinity of a supply of rum, conveniently located in a distant bunker. His men would be without effective leadership, a terrible match for their lack of relevant training.
The last thing to go well with planned attack was the explosion itself. At 4:45 in the morning of 30 July the mine exploded. It created a crater 170 feet long, 60 feet wide and 30 feet deep, almost destroyed two Confederate regiments and a gun battery and created a gap 500 yards long in the Confederate defences.
The Fourth Division had been trained to take advantage, advancing rapidly, avoiding entering the crater itself, securing the flanks of the breach in the lines and hopefully preventing the Confederates from forming a new line further back. Ledlie’s men knew none of this. They advanced slowly towards the scene of devastation. Many went straight down into the crater, instead of splitting left and right around it.
All of this gave the Confederate artillery time to target the crater, slowing down the Union advance even more. Meanwhile, Confederate troops who had fled the area, fearing a second explosion, began to return. A counterattack, organised by William Mahone, soon forced the confused Union attacks back out of the crater, with heavy losses. The Fourth Division managed to get into the battle just in time to take some of these losses.
Union losses in the attack were 3,793, compared to Confederate losses of 1,500 (most in the fighting after the explosion). The attack was a total failure. Grant’s reputation in the North sank. Lincoln’s election hopes looked increasingly doubtful, as all the heavy casualties in the Army of the Potomac appeared to be achieving nothing. Fortunately for both men, further west General Sherman was making more visible progress. At the end of July his armies were coming closer and closer to capturing Atlanta, drawing some of the attention away from Virginia.