Constituted 5 August 1917 as the 78th Division.
Organized 23 August 1917 at Camp Dix, New Jersey.
Inactivated 9 July 1919 at Camp Dix, New Jersey.
Activated in November 1921 with headquarters at Newark, New Jersey.
Ordered into active military service 15 August 1942 and reorganized at Camp Butner, North Carolina, and redesignated as the 78th Infantry Division.
Inactivated 22 May 1946 in Germany.
Activated 1 November 1946 with headquarters in Newark, New Jersey.
Major General Edwin P. Parker Jr. - Assumed command August 1942
Headquarters, 78th Infantry Division
Headquarters Company, 78th Infantry Division
78th Cavalry Reconnaissance Troop
303rd Engineer Combat Battalion
309th Infantry Regiment
310th Infantry Regiment
311th Infantry Regiment
Headquarters and Headquarters Battery, Division Artillery
307th Field Artillery Battalion
308th Field Artillery Battalion
309th Field Artillery Battalion
903rd Field Artillery Battalion
Headquarters, Special Troops
303rd Medical Battalion
778th Ordnance Light Maintenance Company
78th Signal Company
78th Quartermaster Company
Rhineland, Ardennes-Alsace, Central Europe