Raab Collection

Lincoln appointed Grant General-in-Chief in March 1864, and gave him the responsibility for developing Union strategy. He determined to launch a three-pronged attack in both the east and west in the spring. In the west, Sherman would head for Atlanta. In the east, he and General George G. Meade would lead the Army of the Potomac south towards Richmond, while Benjamin Butler's Army of the James would attack the Confederates' "soft underbelly" - first by severing the vital rail-link between Richmond and Petersburg to its south, then advancing on whichever of the cities the opportunity provided.

Grant’s army fought the vicious battles of the Wilderness, Spotsylvania and Cold Harbor, but was unable to either destroy Lee’s Army of Northern Virginia or take Richmond. Butler captured Bermuda Hundred, a peninsula between Richmond and Petersburg, which has the James River on the north and the Appomattox River on the south. Then a much smaller force under Confederate General Beauregard defeated him at Drewry’s Bluff, blunting his move against Richmond, and an expedition he sent to take Petersburg was poorly managed and failed also.

So instead of cutting the rail line, Butler entrenched. Meanwhile, Grant headed towards Petersburg to try and outflank Lee on that front, ending up south of both the James and Appomattox. In June, Union forces made a number of assaults on Confederate works around Petersburg, but these were repulsed with heavy loss. By now Lee’s army had come up, the Confederate fortifications were heavily manned and the greatest Union opportunity to capture Petersburg without a siege was lost. So the siege of Petersburg began.

By the summer of 1864, both sides had their main armies entrenched around that city, which became the key to the survival of the Confederate capital, if not the entire southern war effort. Finding a way to break the impass became Grant’s biggest problem, and in July a potential and promising solution was proposed. Union sappers (men with mining experience) would tunnel under the spot where the opposing lines were closest, and explode an enormous mine beneath the Confederate works, thus blowing a gap in the Confederate defenses of Petersburg. Aided by the element of complete surprise, Federal troops would pour into this gap, outflank the rebels and roll up their army. As an integral part of this strategy, some Union forces, with Butler’s cooperation, would cross north of the James to draw away a portion of the Confederates who might otherwise be available to defend the breach.

The explosion of the mine was planned for July 30. During the night of July 26-27, a Union corps and two divisions of Sheridan’s cavalry under command of Maj. Gen. Winfield Scott Hancock crossed on a pontoon bridge to the north side of the James River to threaten Richmond. One of the brigades assigned this duty was led by Gen. Henry W. Birge, a man who had served with Butler in New Orleans in 1862, but was now part of Hancock and Sheridan’s contingent. If these Union forces managed to draw north just a small force of Confederates, then using their numerical superiority, they could destroy some of the railroad track from Petersburg to Richmond; if a large number of rebels followed, then the movement would have value as a diversion instead. The demonstration did, in fact, divert considerable Confederate forces from the impending attack at Petersburg set for July 30.

On July 29, their diversionary goal accomplished, Grant ordered the Federals to recross the James River. He was anxious to do this as quickly and unobtrusively as possible, so that while he would have the returning men available the next day, the enemy would not realize his forces had gone and their units would be stuck north of the river when the fighting started in the morning.

To speed up his men’s withdrawal, Grant wanted a second pontoon bridge built over the river. Gen. Henry W. Benham was a talented engineer who was particularly efficient in throwing pontoon-bridges across rivers, and was in command of the pontoon department in 1864. He was given the responsibility for laying the second pontoon bridge. Gen. Butler’s army was in a position to cooperate with the troop movements and the building of the bridge, and he received telegrams ordering him to do so. Gen. Birge’s force was to be made available to him if he needed additional support to accomplish his task. One of Grant’s messages to Butler follows.

Autograph Letter Signed, sent as a telegram, July 29, 1864, to Gen. Butler. “Birge’s Brigade will remain at your disposal. I have sent word to Gen. Benham about the bridge.” It is likely you see the telegram sheet looking just like Grant did when he tore it from the pad. During the night of July 29, the Union forces withdrew south, leaving a garrison to hold the bridgehead at Deep Bottom. Texts of the other Grant/Butler exchanges relating to this are included. As Grant summarized this in his Memoirs, “The mine was constructed and ready to be exploded, and I wanted to take that occasion to carry Petersburg if I could. It was the object, therefore, to get as many of Lee's troops away from the south side of the James River as possible. Accordingly, on the 26th, we commenced a movement with Hancock's corps and Sheridan's cavalry to the north side by the way of Deep Bottom, where Butler had a pontoon bridge laid. The plan, in the main, was to let the cavalry cut loose and, joining with Kautz's cavalry of the Army of the James, get by Lee's lines and destroy as much as they could of the Virginia Central Railroad, while, in the mean time, the infantry was to move out so as to protect their rear and cover their retreat back when they should have got through with their work. We were successful in drawing the enemy's troops to the north side of the James as I expected. The mine was ordered to be charged, and the morning of the 30th of July was the time fixed for its explosion...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.” After weeks of preparation, at 4:55 AM on July 30 the Federals exploded the mine, which indeed took the Confederates by surprise and created a huge gap in their defenses. From this propitious beginning, everything deteriorated rapidly for the Union attackers. Unit after unit charged into the crater formed where the mine had gone off, and soldiers milled around in confusion and then found themselves stuck there.

The Confederates quickly recovered and launched several counterattacks. The break was sealed off, and the Federals were repulsed with severe casualties, Ferrarro's division of black soldiers in the crater being very badly mauled. Grant's best chance to end the Siege of Petersburg in 1864 was gone, and all the planning for diversions and for follow-up operations was for nought. Instead, the soldiers settled in for another eight months of trench warfare.