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Caldron of Hell: The Battle of the Crater


After a month of toiling underground, the soldiers of Union Colonel Henry Pleasants’ 48th Pennsylvania Volunteer Infantry Regiment were ready to unleash a fiery surprise against the well-entrenched Confederate defenders of Petersburg, Virginia. Roughly 150 yards from a section in the center of the Union line at Petersburg was a salient in the Rebel line, where a stout redoubt had been built on high ground. “We could blow that damn fort out of existence if we could run a mine shaft under it,” vowed one of the men in Pleasants’ regiment, an outfit that contained many coal miners. After digging a tunnel more than 500 feet long under the Confederate line and packing it with eight thousand pounds of explosives, the miners were in a prime position to strike a mighty blow for the Union. If their mine could punch a hole through the enemy line and Federal infantry was able to push forward in time to exploit the breach, the Army of the Potomac might very well attain the great breakthrough it needed in what had developed into a bloody stalemate against General Robert E. Lee and his vaunted Army of Northern Virginia. The sparks would fly on July 30, 1864 in what has ever after been remembered as the Battle of the Crater.

Guided by the hand of the new Union General-in-Chief, Lieutenant General Ulysses S. Grant, the Army of the Potomac had embarked on a new campaign against Lee and the Army of Northern Virginia in May 1864. For several weeks, the two armies engaged in some of the most horrific and unforgiving fighting of the American Civil War across several battlefields that came to resemble hell on earth. The fighting that took place around the Confederate capital of Richmond, Virginia between May 4 and June 15 was so relentless that the two sides suffered some 88,000 combined casualties, averaging out to about 2,100 casualties per day during that span.

Ferocious combat between the Army of the Potomac and the Army of Northern Virginia at the Bloody Angle during the Battle of Spotsylvania Court House in May 1864. Print by Mort Künstler. (Photo Credit: Mort Künstler)

Following this unforgiving period of slaughter, Grant pulled off a daring maneuver, marching his forces around Lee’s army, crossing the James River, and driving his men toward the vital railroad hub of Petersburg. Lee was forced to rush his troops to save the city, and although the Union failed to capture the stronghold when it was still lightly defended, Grant did succeed in bottling up the Army of Northern Virginia at Petersburg. With the enemy maintaining very strong defenses, Grant ultimately initiated a siege of the city that Richmond and Lee’s army depended upon for supplies. Once Petersburg fell, so too would Richmond and the Army of Northern Virginia.

The siege of Petersburg quickly turned into a stalemate. Just two weeks after the Union began to invest the city, the battle lines of the Army of the Potomac and the Army of Northern Virginia had hardly moved. As the days passed by without any movement and the two sides anxiously stared each other down from their entrenchments, the Union needed a breakthrough. Colonel Pleasants of the 48th Pennsylvania thought that potential breakthrough was found when he overheard one of his soldiers propose running “a mine shaft under” the Confederate lines and blowing a section of the enemy defenses to kingdom come. Pleasants, who had been a mining engineer before the Civil War, brought this idea to his division commander. It then made its way up the chain of command and was approved by the army’s 9th Corps Commander, Major General Ambrose Burnside.

On June 25, 1864, Pleasants’ men began to carve out their secret underground tunnel. The project was such an undertaking that even the army’s engineers doubted its feasibility, one of whom considered it “claptrap and nonsense.” Nonetheless, the coal miners of the 48th Pennsylvania persevered. Using primitive tools, collecting their own lumber to timber the shaft, ingeniously finding a way to ventilate the tunnel with fresh air, and facing obstructions like underground springs and quicksand, the miners completed the initial excavation by July 23. Their shaft ran 511 feet long “with lateral galleries at the end each nearly forty feet long under the Confederate line,” as noted by historian James M. McPherson. The tunnel was packed with eight thousand pounds of explosives and scheduled to be ignited at dawn on Saturday, July 30.

Colonel Pleasants and his miners packing their tunnel with explosives. (Photo Credit: Wikimedia Commons)

Although initially skeptical about this mining enterprise, General Grant and the commander of the Army of the Potomac, Major General George G. Meade, changed their tune after seeing the skilled work of the Pennsylvania miners. Grant subsequently ordered movements by a corps under Major General Winfield S. Hancock and cavalry under Major General Philip Sheridan with the intention of misdirecting Lee. It worked, and according to McPherson, this diversion succeeded in pulling “several of Lee’s divisions away from the Petersburg front.”

General Burnside was given the green light by Grant and Meade to detonate the mine on the scheduled date and to send his corps forward into the fiery breach in the enemy line. This opportunity to capture Petersburg and win the war was Burnside's golden chance at redemption. In December 1862, Burnside had been in command of the Army of the Potomac and presided over one of the most disastrous defeats of the war at the Battle of Fredericksburg. Now, he readied his troops for this mighty undertaking. With three of his divisions still recovering from the relentless period of combat earlier in the campaign, Burnside selected his Fourth Division, which comprised two brigades of United States Colored Troops (USCT) under Brigadier General Edward Ferrero, to spearhead the attack. With the expectation that the detonation of the mine would leave a crater where the Rebel redoubt had once stood, historian Richard S. Slotkin writes that the black troops received “special training in the maneuvers required to pass the breach and storm the high ground.” Ferrero’s soldiers were determined “to show the white troops what the colored division could do,” as said by one officer.

Despite the special training the USCTs had received and their eagerness to lead the assault, in the hours before the operation began, General Meade ordered Burnside to launch the attack with his white divisions first. As McPherson explains, “Meade’s motive seems to have been lack of confidence in the inexperienced black troops. . . .” Grant gave Meade approval to issue this order and later explained before the Committee on the Conduct of the War: If the attack went badly, “it would then be said . . . that we were shoving these people ahead to get killed because we did not care anything about them. But that could not be said if we put the white troops in front.”

Lieutenant General Ulysses S. Grant and Major General George G. Meade. (Photo Credit: Wikimedia Commons - Grant | Meade)

With Ferrero’s division now held back, Burnside’s other three division commanders drew slips to determine who would lead the attack. The winner was Brigadier General James H. Ledlie, a man who one officer described as “a drunkard and an arrant coward,” also adding, “It was wicked to risk the lives of men in such a man’s hands.” When the action finally unfolded, Ledlie made it abundantly clear why he was held in such poor esteem by his comrades.

At three o’clock on the morning of July 30, the mine’s fuse was lit and the soldiers of Burnside’s 9th Corps anxiously awaited the fireworks. As historian H.W. Brands records, when nothing happened, “Two intrepid miners crawled along the tunnel to find out what had gone wrong; they discovered that the fuse had failed at a splicing point.” After relighting the fuse and hurrying out of the tunnel, the countdown to Confederate armageddon resumed. Shortly before 5 a.m., the mine exploded, and its destructive power reverberated across the landscape. As one observer in blue described it, “Suddenly the earth trembled under our feet. An enormous mass sprang into the air. A mass without form or shape, full of red flames, and carried on a bed of lightning flashes, mounted towards heaven with a detonation of thunder.” McPherson reports that the blast left “a hole 170 feet long, 60 feet wide, and 30 feet deep,” and also buried an entire Confederate regiment and an artillery battery in the debris. Stunned by this shattering destruction, Rebel troops on either side of the crater took flight.

Before Petersburg at sunrise, July 30th 1864 by Alfred Waud. (Photo Credit: Wikimedia Commons)

Before the Union infantry went forward, roughly 110 Federal cannon and 50 mortars dealt out further punishment to the enemy. Unfortunately for the Army of the Potomac, however, the resulting actions on this day proved to be disastrous. Although Grant had instructed Burnside that his corps should not “stop in the crater at all but push on to the top of the hill,” those instructions were not followed. Unlike the training that General Ferrero’s UCSTs had received, Burnside’s other soldiers were unprepared and made fatal errors. Living up to his reputation as “a drunkard,” General Ledlie remained behind in the trenches drinking a bottle of rum while his division charged into the breach and got stuck. As historian Ron Chernow explains, “Instead of circumventing the breach, the troops had tried to rush through it and were trapped by the Crater’s steep sides.” A terrifying slaughter soon commenced as the Confederates rallied and fought back.

After recovering from the shock of the mine explosion, Confederate soldiers on either side of the crater found they had a perfect killing zone to exact their revenge. As McPherson reports, Burnside’s other two “white divisions did little better” than Ledlie’s troops and degenerated “into a disorganized mob as Rebel artillery and mortars found the range and began shooting at the packed bluecoats in the crater as at fish in a barrel.” The carnage was horrific as the Confederate defenders tossed grenades into the crater and punished the struggling Federals with withering fire from both flanks. “The shouting, screaming, and cheering,” wrote one of Grant’s aides, “mingled with the roar of the artillery and the explosion of shells, created a perfect pandemonium . . . the crater had become a caldron of hell.”

The Battle of the Crater by Tom Lovell. (Photo Credit:

General Ferrero’s division was belatedly added to the fight by Burnside, and while the USCTs battled bravely, there was little they could do to turn the tide in a fight that had been executed so poorly from the start and lacked firm leadership or direction from the top levels of command. As McPherson adds, the black soldiers also “caught the brunt of” a fierce Confederate counterattack led by Major General William Mahone and faced very harsh retaliation, among which included the cold-blooded murder of several USCTs who tried to surrender. Mahone’s counterassault ultimately succeeded in beating back the remnants of the Federal assault and repaired the breach in the Rebel line.

The crater operation had seemed to shape up so well for the Union and offered a tremendous opportunity to attain a war-winning breakthrough. Due to poor leadership and execution, however, it ended in miserable failure. The defeat cost the Union some 4,000 casualties and approximately 1,800 for the Confederates. Burnside was relieved of command for the fiasco and Ledlie later resigned his commission in disgrace. General Grant summed up the disaster when he wrote, “It was the saddest affair I have witnessed in the war. Such opportunity for carrying fortifications I have never seen and do not expect again to have.” The siege of Petersburg would rage on for another eight months before Grant and the Army of the Potomac finally broke through in the spring of 1865. After the fall of Petersburg and Richmond, General Lee ultimately surrendered what remained of the Army of Northern Virginia to Ulysses S. Grant at Appomattox Court House on April 9.

Header Photo Credit: Mahone's Counterattack at the Battle of the Crater by Don Troiani.


American Battlefield Trust: Battle of the Crater.

American Battlefield Trust: Calamity in the Crater.

American Battlefield Trust: Grant's Overland Campaign.

Essential Civil War Curriculum: The Battle of the Crater.

Grant by Ron Chernow. Petersburg Campaign.

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