Oak Grove

On June 25, 1862, fighting broke out in Henrico County, Virginia, in what became known as the Battle of Oak Grove, sometimes called the Battle of French's Field or King's School House. It marked the opening engagement of the Seven Days Battles during the Peninsula Campaign of the American Civil War. Seeking to push Richmond within striking distance of his siege guns, Maj. Gen. George B. McClellan moved his lines forward. Two Union divisions from the III Corps pressed across the headwaters of White Oak Swamp, only to be driven back by Confederate forces under Maj. Gen. Benjamin Huger. Stationed three miles behind the action, McClellan first wired orders halting the assault, then reversed course once he reached the front, directing his men to renew the attack over identical terrain. Nightfall finally brought the combat to a close. In the end, Union forces advanced merely 600 yards, while both sides together suffered more than a thousand casualties.

Battle

On the morning of June 25, at half past eight, three brigades of Union soldiers advanced in a neat battle formation. Brig. Gen. Daniel E. Sickles led the Excelsior Brigade on the right, Brig. Gen. Cuvier Grover held the center, both under Hooker's command, while Brig. Gen. John C. Robinson, serving under Kearny, anchored the left. Robinson and Grover pushed forward steadily enough, but Sickles's New York troops ran into trouble, first tangling in abatis, then struggling through the swamp's upper reaches, and finally facing determined Confederate defense. These combined obstacles disrupted the Federal formation. Seizing this opening, Huger sent Brig. Gen. Ambrose R. Wright's brigade forward in a counterattack aimed squarely at Grover's men.

The chaos deepened when it became clear that one of Wright's Georgia regiments was dressed in red Zouave garb, an outfit many of Grover's soldiers assumed belonged exclusively to their own side. This mistaken belief made them hesitant to fire, until they realized no Union troops would be coming from Richmond's direction, at which point they finally opened fire. The battle turned at a critical moment when the 26th North Carolina, part of Brig. Gen. Robert Ransom's brigade and facing combat for the first time, unleashed a precisely timed rifle volley into Sickles's ranks. This blow shattered the momentum of his stalled advance and sent the 71st New York fleeing in what Sickles himself later called "disgraceful confusion."

Once word of Sickles's setback reached Heintzelman, the corps commander pushed reinforcements toward the front and alerted McClellan, who was directing the battle from a telegraph line some three miles (4.8 km) removed from the action. Lacking a clear picture of what had actually happened, McClellan grew anxious and, at 10:30 in the morning, commanded a full withdrawal to the entrenchments, a decision that left his officers on the ground baffled. He then wired that he intended to come to the front himself, a message that brought roughly two and a half hours of inactivity to the fighting. By 1 p.m., having concluded that matters were less dire than he had thought, McClellan reversed course and ordered his troops to push forward again, reclaiming ground they had already fought for earlier that same day. The combat continued without pause until darkness fell.

Aftermath

This small clash marked the lone instance of McClellan pushing forward against Richmond in an offensive move. What he gained was a mere 600 yards, roughly 550 meters, purchased with more than 1,000 men killed, wounded, or captured on both sides combined. Such a modest advance did nothing to disrupt the campaign Lee had already put into motion. On the following day, Lee took command of events by launching an assault at Beaver Dam Creek, situated north of the Chickahominy River near Mechanicsville. That clash opened the Seven Days fighting and set in motion a strategic withdrawal by the Union Army.