The Battle of Petersburg represented U.S. Grant’s best chance of a significant victory in his 1864 campaigns in Virginia (American Civil War). During May and early June, his armies had been engaged in near constant combat with Robert E. Lee’s Army of Northern Virginia. During that period the two armies had moved from the Wilderness area north of Richmond round to Cold Harbor east of the Confederate Capitol. During that time Grant had made repeated attempts to get around Lee’s right wing, and Lee had successfully blocked them all. Grant was hoping to force Lee to fight on open ground, away from his lines of entrenchments, where Grant’s superior numbers should be decisive.
After the failure of an attack at Cold Harbor (3 June), it became obvious to Grant that he could not achieve his objectives around Richmond. Grant’s predecessors in command of the Army of the Potomac would have withdrawn to the north at this point (if any of them had got this far). That was not Grant’s way. From his base at White House (the same place McClellan had used during the Peninsula Campaign) Grant looked for some way to break the deadlock.
He quickly decided on a course of action. His original plans had included an expedition south of the James River, aimed at cutting Richmond’s supply lines from the south. This Bermuda Hundred campaign had come to grief at Drewry’s Bluff (16 May 1864), after which General Butler and the Army of the James had allowed themselves to be bottled up between the James and Appomattox Rivers. As Grant had approached from the north, he had used the Army of the James as a source of reinforcements, using W.F. Smith’s Eighteenth Corps at the Battle of Cold Harbor. There it suffered some of the heaviest losses in the army.
Grant now decided to move almost his entire army south of the James, and use it to cut most of the supply lines into Richmond from the south. Three of the four railroads running into Richmond met at Petersburg, with a single line linking the two cities. If Grant could get his men into Petersburg, then Lee might be forced to launch a counter attack, or even pull out of Richmond completely. This was indeed what happened when, eventually, Grant was actually able to cut those railroad links. Unfortunately for him, it was going to take nearly a year to achieve that result.
The move to the south of the James began very well. On the night of 12-13 June the Army of the Potomac withdrew from its trenches around Cold Harbor. W.F. Smith’s corps was sent back to Butler by boat, arriving first. The four corps of the Army of the Potomac marched to the James River, where Union engineers had constructed one of the longest Pontoon bridges in military history, over 2,000 feet long. Meanwhile, back at Cold Harbor Sheridan with a cavalry division had ordered to confuse Lee as much as possible. Over the next few days he succeeded to such a great extent that it would take until 18 June for Lee to finally catch on to what was happening.
By then it should have been too late. Petersburg had impressive fortifications, but almost no defenders. The Confederate commander in the city, General Beauregard, had lost some of his men to Lee at Richmond, while most of the rest were in the trenches at Bermuda Hundred, facing the Army of the James. On 15 June Beauregard only had 2,200 men at Petersburg. For most of the next four days Grant would have enough men outside Petersburg for any really determined attack to have captured it.
Their first chance came on 15 June. General Smith’s corps was 18,000 strong, even after Cold Harbor. A well planned attack at any point on Beauregard’s thinly defended lines could have punched straight through them, and there was nobody to defend the inner defences. However, in Smith’s defence he had no way to tell just how weak the Confederate defence was, and his corps had suffered a bad mauling at Cold Harbor, attacked significantly less impressive fortifications. Despite this, it should not have taken him until seven in the evening to launch his attack. When that attack went in, it succeeded in capturing much of the first line of defences. Five of the thirteen Confederate redans were captured. Beauregard later stated that at this point Petersburg was ‘at the mercy of the Federal commander, who had all but captured it.’
Unfortunately, that was where Smith stopped for the night. The rather cumbersome commander structure in Grant’s armies also played a part in the failures of the first day. He had decided to send Hancock’s corps to help Smith’s attack. To do this he had to issue the orders to General Meade, still commanding the Army of the Potomac, who then had to get them to Hancock. On this occasion the orders never reached Hancock, who only learnt that he was expected at Petersburg when he received a message from Smith.
Despite this first failure, the Union forces were given another chance on the next day. Despite evidence from Beauregard, Lee did not believe that Grant was crossing the James. Beauregard was forced to rely on his own resources. He had no choice but to pull his troops out of the lines at Bermuda Hundred. Even after doing this, he still only mustered 10,000 men. Facing him were now three entire Union corps – Smith’s, Burnside’s and Hancock’s – containing over 50,000 men.
Once again slow movement delayed the start of the Union attack on 16 June until late in the afternoon. When it did start the Union attack did not have the vigour it needed to carry the Confederate lines. Some local success was achieved, but Union veterans were increasingly unwilling to go forward to attack strong defences.
The next day saw the Union side reinforced again. Warren’s corps arrived, bringing it Federal concentration up to nearly 70,000 men. Beauregard had no such luck. 1,200 men arrived during the day, but otherwise his force was much as it had been on the previous day. The fighting on 17 June lasted all day, but achieved little. However, it did convince Beauregard that he had to abandon his current lines. Overnight on 17-18 June his force pulled back to a new line, just outside Petersburg itself.
Fortunately for him, Lee was finally convinced that a major attack was taking place south of the James. During the morning of 18 June he and his army began to arrive in the new lines around Petersburg. Lee him self arrived at about 11.30. Even this might have been too late. A ‘grand attack’ had been ordered for early in the morning of 18 June. However, when the attackers discovered the empty Confederate trenches abandoned overnight, instead of continuing on to attack the new lines, they stopped. By the time a new attack could be organised it was too late. Lee now had over 40,000 men in the Petersburg lines, more than enough to defend them against any Federal attack, not least one being launched by an almost exhausted army.
Grant now acknowledged the state of his army. For the first time since the start of May, his army was given rest (or a relative rest anyway – constant small scale fighting continued between the two lines continued until the end of the siege in the following April, regardless of whatever major actions were happening at the time). Another attempt to break the Petersburg lines was made at the end of July (Battle of the Crater). After that failed, Grant concentrated on cutting the railroads into Petersburg, forcing Lee to extend his lines ever further to the south and west.