We dug into the ECW archives and found Chris Mackowski’s post from 2013 to answer the question. Here’s the original article, recounting Lincoln’s Dec. 22, 1862, circular: A Post-Fredericksburg Message From Lincoln To The Army
Just to put things in perspective, here are some brief, fast-facts on the First Battle of Fredericksburg.
Dates: December 11-15, 1862 (most of the fighting and mass assaults took place on December 13)
Commanding Generals: Union – Ambrose Burnside, Confederate – Robert E. Lee
Positions: Union – attacking, Confederates – defending
Casualties: Union – approximately 13,300, Confederate – 4,500
Outcome: Confederate victory; no significant change in the strategic situation; Burnside removed from command about six weeks later
Re-read the casualty numbers, then read Lincoln’s message: A Post-Fredericksburg Message From Lincoln To The Army