Who replaced generall McClellan in the civil war?

General Ambrose Burnside replaced General George B. McClellan as the commander of the Army of the Potomac during the American Civil War. Burnside took command in November 1862, following McClellan's removal after the Battle of Antietam. His leadership was marked by the significant defeat at the Battle of Fredericksburg in December 1862, which further affected Union morale and strategy.