From Project Gutenberg (Volume VI):
CONGRATULATIONS TO THE ARMY OF THE POTOMAC
EXECUTIVE MANSION, WASHINGTON,
December 22, 1862.
TO THE ARMY OF THE POTOMAC:
I have just read your general’s report of the battle of Fredericksburg. Although you were not successful, the attempt was not an error, nor the failure other than accident. The courage with which you, in an open field, maintained the contest against an intrenched foe, and the consummate skill and success with which you crossed and recrossed the river in the face of the enemy, show that you possess all the qualities of a great army, which will yet give victory to the cause of the country and of popular government.
Condoling with the mourners for the dead, and sympathizing with the severely wounded, I congratulate you that the number of both is comparatively so small.
I tender to you, officers and soldiers, the thanks of the nation.
A. LINCOLN.
You can read General Burnside’s account of the battle in the January 3, 1863 issue of Harper’s Weekly hosted at Son of the South. Of the approximately 9,000 Union wounded, “The surgeons report a much larger proportion of slight wounds than usual, 1632 only being treated in hospitals.”