Prelude to the Battle
McClellan’s Peninsula Campaign
On March 17, 1862, Union General George B. McClellan launched his Peninsula Campaign. After transporting the Army of the Potomac by ships to the Virginia peninsula between the York and James Rivers, McClellan planned to advance on Richmond and bring the American Civil War to a quick conclusion. By late May, the Federals had fought their way to the outskirts of the Confederate capital.
Battle of Seven Pines
On May 31, Confederate General Joseph E. Johnston struck back at the Battle of Seven Pines. Two days of hard fighting rendered a tactical draw and high casualties on both sides. The aftermath of the engagement, however, produced two important strategic developments. First, Robert E. Lee assumed command of the Army of Northern Virginia after Johnston suffered a severe wound during the fighting. Second, the high casualty rate convinced McClellan to invest Richmond rather than to risk costly assaults against the Rebel defenses around the capital.
Reprieve for Lee
For nearly a month, McClellan sat idly, developing plans for a siege. The unexpected reprieve presented Lee with an opportunity to organize his command and to plan an offensive designed to drive the Union army away from Richmond. Toward the end of June, McClellan developed a renewed sense of urgency when he learned that Major General Stonewall Jackson was moving to reinforce Lee after concluding his highly successful Shenandoah Valley Campaign.
Clash at Oak Grove
McClellan Orders Union Advance
On June 25, McClellan ordered three Union brigades, under the overall command of Major General Samuel P. Heintzelman, to advance west along the Williamsburg Road toward Richmond. Two of the brigades, led by Brigadier-General Daniel E. Sickles and Brigadier-General Cuvier Grover, were part of Major General Joseph Hooker’s division. The other brigade, led by Brigadier-General John C. Robinson, was from Brigadier-General Philip Kearny’s division.
McClellan’s objective was to advance his siege artillery approximately one and one-half miles closer to the Southern capital by taking the high ground on Nine Mile Road around Old Tavern. His new plan was to “shell the city and take it by assault.” Directly in the Federals’ path was a dense forest of oak trees known locally as Oak Grove. Benjamin Huger’s Division of South Carolinians awaited the Northerners on the other side of the trees.
Federals Attack and Rebels Counterattack
Initially, Robinson and Grover made good progress on the left and in the center. Swampy ground, however, slowed Sickles’s men. As the Yankee advance slowed, Huger ordered a counterattack by Brigadier-General Ambrose R. Wright’s brigade against the Federal center, bringing the Union advance to a halt.
Meanwhile, Sickle’s men encountered Brigadier-General Robert Ransom’s brigade on the Union right. The ensuing skirmish sent the Yankees fleeing, prompting Hooker to request more men. Heintzelman provided reinforcements, but he also forwarded Hooker’s request to McClellan, who was trying to manage the battle from a position three miles in the rear. After reading Hooker’s dispatches, McClellan ordered a general retreat, just as Sickle’s reinforced brigade began to rally. McClellan then headed off to the front, as his men sat idle for two and one-half hours awaiting orders.
Upon arriving at the front, McClellan ordered his men back into battle, over the same ground that they had conceded earlier. The fighting continued until nightfall, but the Northerners accomplished little.
Aftermath of the Battle
By the end of the day, the Federals had advanced only 600 yards at an estimated cost of 626 casualties (68 dead, 503 wounded and 55 missing and captured). The Confederacy lost roughly 441 soldiers (66 killed, 362 wounded, and 13 missing and captured).
Insignificant as the Federal gains were, some historians consider the Battle of Oak Grove to be the high-water mark of the Peninsula Campaign. On the next day, Lee launched a major offensive that sent McClellan away from Richmond’s gates and nearly back to the James River by July 1.
By August, Northern authorities recalled the Army of the Potomac to the Washington, DC, area to deal with Lee’s Northern Virginia Campaign.