The division was subsequently relieved by the U.S. 36th Infantry Division. The 12th Armored Division suffered over 1,700 battle casualties during the fighting in and around Herrlisheim. As a consequence, when African-American soldiers who were in non-combat positions were able to volunteer to become combat troops, Major General Roderick R. Allen was one of only ten division commanders who allowed them to join the combat ranks. After recovering from the bruising experience at Herrlisheim, the 12th went over to the offensive and attacked south from Colmar, after being assigned to the French First Army under General Jean de Lattre de Tassigny. In a lightning drive, the 12th effected junction with French forces at Rouffach, on 5 February, sealing the Colmar Pocket and ending German resistance in the Vosges Mountains. Except for elements acting as a protective screen, the division withdrew to the St. Avold area for rest and rehabilitation. The division was attached to the Third Army under General George S. Patton, Jr., on 17 March 1945 through its crossing of the Rhine on 28 March. The soldiers were ordered to remove their identifying unit insignias and vehicle markings were painted over, disguising the fact that Patton had an additional tank division under his command. Thus the 12th was given the nickname the "Mystery Division". The attack resumed on 18 March 1945.