Chancellorsville, Battle of one of the great battles of the Civil War. It was fought May 2–4, 1863, at Chancellorsville, Virginia, about 55 miles (89 km) northwest of Richmond. General Joseph Hooker, with 130,000 Union troops, attacked 60,000 Confederates under General Robert E. Lee. Lee detached General Thomas J. (“Stonewall”) Jackson to attack the exposed flank of the Union forces. Jackson surprised and routed the 11th Corps under General O. O. Howard. Late in the battle Jackson was mistakenly fired on by his own men and mortally wounded. Hooker withdrew toward Fredericksburg. He lost 17,200 men killed, wounded, or captured, and the Confederates 12,400.