Noting the difficult progress of all Allied units against German resistance in the Colmar Pocket, General de Lattre requested reinforcements from the U.S. 6th Army Group. Concurring, General Devers subordinated the Headquarters of the U.S. XXI Corps to the French First Army. General Milburn's XXI Corps took up position between the two French corps on 28 January and assumed command of the U.S. 3rd and 28th Infantry Divisions. Two additional U.S. divisions were also assigned to the XXI Corps - the U.S. 75th Infantry Division and the U.S. 12th Armored Division. Finally, the French 5th Armored Division, 1st Parachute Regiment, and 1st "Choc" (commando) Battalion were placed under XXI Corps' command. The XXI Corps was given the mission of capturing the city of Colmar and driving on the bridge at Breisach.