Constituted 10 December 1942 as the 66th Infantry Division.
Activated 13 April 1943 at Camp Blanding, Florida.
Inactivated 8 November 1945 at Camp Kilmer, New Jersey.
Major General Herman F. Kramer - Assumed command April 1943
Headquarters, 66th Infantry Division
Headquarters Company, 66th Infantry Division
66th Cavalry Reconnaissance Troop
266th Engineer Combat Battalion
262nd Infantry Regiment
263rd Infantry Regiment
264th Infantry Regiment
Headquarters and Headquarters Battery, Division Artillery
721st Field Artillery Battalion
870th Field Artillery Battalion
871st Field Artillery Battalion
872nd Field Artillery Battalion
Headquarters, Special Troops
366th Medical Battalion
701st Ordnance Light Maintenance Company
566th Signal Company
66th Quartermaster Company
Northern France