The Battle of Chancellorsville, a major war, took place between April 30 and May 6, 1863, and was a Confederate victory due to the brilliant strategy employed by Gen. Robert E. Lee. Union Maj. Gen. Joseph Hooker’s Army of the Potomac was more that twice the size of the Confederate troops. Lee made a risky decision to divide his army in the presence of a much larger enemy force. This battle is known as Lee’s “perfect battle.”

from Wikipedia