The Battle of Seven Pines, also known as the Battle of Fair Oaks, took place from May 31 to June 1, 1862, during the American Civil War. It was fought near Richmond, Virginia, between the Union Army led by General George B. McClellan and the Confederate Army commanded by General Joseph E. Johnston. The battle was part of the Peninsula Campaign, aimed at capturing Richmond. The battle resulted in heavy casualties on both sides, with approximately 36,000 soldiers engaged. Although the Confederates initially gained ground, the Union forces held their positions. General Johnston was wounded, leading to General Robert E. Lee taking command of the Confederate forces, which would significantly impact the war's progression.