The Battle of Seven Pines, also known as the Battle of Fair Oaks, was a major American Civil War battle which occurred from 31 May to 1 June 1862 in Henrico County, Virginia.
Union general George B. McClellan's 110,000-strong Army of the Potomac had advanced to within nine miles of the Confederate capital of Richmond, Virginia after taking Yorktown and Williamsburg during his Peninsula Campaign, but he wrongly feared that the Confederate forces in Richmond outnumbered him, and he resolved to wait for reinforcements outside of the city. By late spring, George McClellan's army was divided in two by the flooded Chickahominy River, so, on 31 May, the Confederate general Joseph E. Johnston and his 39,000-strong army attacked the smaller federal corps at the crossroads of Seven Pines. The Confederate attack drove back IV Corps and inflicted heavy losses, so the Union sent in III Corps and John Sedgwick's division of Edwin V. Sumner's II Corps to counterattack, stabilizing the federal position. Johnston was severely wounded in the battle and carried from the field, and command temporarily devolved to Gustavus Woodson Smith before Robert E. Lee later assumed command of the army. The Confederates withdrew after a second failed attack on 1 June, and the more aggressive Lee would take command of the army and attack again in the Seven Days Battles of 25 June-1 July 1862.