(Dec. 13, 1862) Engagement of the American Civil War fought at Fredericksburg, Va. , that resulted in a decisive victory for the Confederate forces. Over 120,000 Union troops under Ambrose E. Burnside were met at Fredericksburg by an entrenched Confederate force of 78,000 under Robert E. Lee. The Union attack failed, resulting in more than 12,500 casualties compared to 5,000 for the Confederates. Burnside was relieved of his command, and the victory restored Confederate morale lost after the defeat in the Battle of Antietam