The Third Battle of Petersburg, also known as the Breakthrough at Petersburg or the Fall of Petersburg, was fought on April 2, 1865, south and southwest Virginia in the area of Petersburg, Virginia, at the end of the 292-day Richmond–Petersburg Campaign (sometimes called the Siege of Petersburg) and in the beginning stage of the Appomattox Campaign near the conclusion of the American Civil War. The Union Army (Army of the Potomac, Army of the Shenandoah and Army of the James) under the overall command of General-in-Chief Lieutenant General Ulysses S. Grant, launched an assault on General Robert E. Lee's Confederate Army of Northern Virginia's Petersburg, Virginia, trenches and fortifications after the Union victory at the Battle of Five Forks on April 1, 1865. As a result of that battle the Confederate right flank and rear were exposed. The remaining supply lines were cut and the Confederate defenders were reduced by over 10,000 men killed, wounded, taken prisoner or in flight.
The thinly held Confederate lines at Petersburg had been stretched to the breaking point by earlier Union movements that extended those lines beyond the ability of the Confederates to man them adequately and by desertions and casualties from recent battles. As the much larger Union forces assaulted the lines, desperate Confederate defenders held off the Union breakthrough long enough for Confederate government officials and most of the remaining Confederate army, including local defense forces and some Confederate Navy personnel, to flee Petersburg and the Confederate capital of Richmond, Virginia, during the night of April 2–3. Confederate corps commander Lieutenant General A.P. Hill was killed during the fighting.
Union soldiers occupied Richmond and Petersburg on April 3, 1865, but most of the Union Army pursued the Army of Northern Virginia until they surrounded it, forcing Robert E. Lee to surrender that army on April 9, 1865, after the Battle of Appomattox Court House, Virginia.
The 292-day Richmond–Petersburg Campaign (Siege of Petersburg) began when two corps of the Union Army of the Potomac, which were unobserved when leaving Cold Harbor at the end of the Overland Campaign, combined with the Union Army of the James outside Petersburg, but failed to seize the city from a small force of Confederate defenders at the Second Battle of Petersburg on June 15–18, 1864. Union General-in-Chief Ulysses S. Grant then had to conduct a campaign of trench warfare and attrition in which the Union forces tried to wear down the smaller Confederate Army, destroy or cut off sources of supply and supply lines to Petersburg and Richmond and extend the defensive lines which the outnumbered and declining Confederate force had to defend to the breaking point. The Confederates were able to defend Richmond and the important railroad and supply center of Petersburg, Virginia, 23 miles (37 km) south of Richmond for over nine months against a larger force by adopting a defensive strategy and skillfully using trenches and field fortifications.
After the Battle of Hatcher's Run on February 5–7, 1865, extended the lines another 4 miles (6.4 km), Lee had few reserves after manning the lengthened defenses. Lee knew that his forces could not sustain the defenses much longer and the best chance to continue the war was for part or all of his army to leave the Richmond and Petersburg lines, obtain food and supplies at Danville, Virginia, or possibly Lynchburg, Virginia, and join General Joseph E. Johnston's force opposing Major General William T. Sherman's army in North Carolina. If the Confederates could quickly defeat Sherman, they might turn back to oppose Grant before he could combine his forces with Sherman's. Lee began preparations for the movement and informed Confederate President Jefferson Davis and Confederate States Secretary of War John C. Breckinridge of his conclusions and plan.
Under pressure from President Jefferson Davis to maintain the defenses of Richmond and unable to move effectively over muddy roads with poorly fed animals in winter in any event, General Lee accepted a plan by Major General John B. Gordon to launch an attack on Union Fort Stedman designed to break Union lines east of Petersburg or at least compel Grant to shorten the Union Army lines. If this were to be accomplished, Lee would have a better chance to shorten the Confederate lines and send a substantial force, or nearly his whole army, to help Joe Johnston.
Gordon's surprise attack on Fort Stedman in the pre-dawn hours of March 25, 1865, captured the fort, three adjacent batteries and over 500 prisoners while killing and wounding about 500 more Union soldiers. The Union IX Corps under Major General John G. Parke promptly counterattacked. The IX Corps recaptured the fort and batteries, forced the Confederates to return to their lines and in places to give up their advance picket line. The IX Corps inflicted about 4,000 casualties, including about 1,000 captured, whom the Confederates could ill afford to lose.
On the afternoon of March 25, 1865, at the Battle of Jones's Farm, the II Corps and VI Corps captured Confederate picket lines near Armstrong's Mill which extended the left end of the Union line about 0.25 miles (0.40 km) closer to the Confederate fortifications. This put the VI Corps within about 0.5 miles (0.80 km) of the Confederate line. After the Confederate defeats at Fort Stedman and Jones's Farm, Lee knew that Grant soon would move against the only remaining Confederate supply lines to Petersburg, the South Side Railroad and the Boydton Plank Road, and possibly cut off all routes of retreat from Richmond and Petersburg.
Beginning of Appomattox Campaign
On March 24, 1865, the day before the Confederate attack on Fort Stedman, Grant already planned for an offensive to begin March 29, 1865. The objectives were to draw the Confederates out into an open battle where they might be defeated and, if the Confederates held their lines, to cut the remaining road and railroad supply and communication routes between areas of the Confederacy still under Confederate control and Petersburg and Richmond. The Battle of Fort Stedman had no effect on Grant's plans. The Union Army lost no ground due to the attack, did not need to contract their lines and suffered casualties that were only a small percentage of their force.
Grant ordered Major General Edward Ord to move part of the Army of the James from the lines near Richmond to fill in the line to be vacated by the II Corps under Major General Andrew A. Humphreys at the southwest end of the Petersburg line before that corps moved to the west. This freed two corps of Major General George Meade's Army of the Potomac for offensive action against Lee's flank and railroad supply lines: Major General Andrew A. Humphrey's II Corps and the V Corps commanded by Major General Gouverneur K. Warren. Grant ordered the two infantry corps, along with Major General Philip Sheridan's cavalry corps, still designated the Army of the Shenandoah under Sheridan's command, to move west. Sheridan's cavalry consisted of two divisions commanded by Brigadier General Thomas Devin and Brigadier General (Brevet Major General) George Armstrong Custer but under the overall command of Brigadier General (Brevet Major General) Wesley Merritt, as an unofficial corps commander, and the division of Major General George Crook detached from the Army of the Potomac. Grant's objectives remained the same although he thought it unlikely the Confederates would be drawn into open battle.
Confederate General-in-chief Robert E. Lee, who was already concerned about the ability of his weakening army to maintain the defense of Petersburg and Richmond, realized that the Confederate defeat at Fort Stedman would encourage Grant to make a move against his right flank and communication and transportation routes. On the morning of March 29, 1865, Lee prepared to send some reinforcements to the western end of his line and began to form a mobile force of about 10,600 infantry, cavalry and artillery under the command of Major General George Pickett and cavalry commander Major General Fitzhugh Lee. This force would go beyond the end of the line to protect the key junction at Five Forks in Dinwiddie County from which a Union force could access the remaining open Confederate roads and railroads.