World War I The 378th Infantry Regiment was constituted on September 4, 1918, as a unit of
World War I's
National Army and assigned to the 189th Infantry Brigade, a unit of the
95th Division. The division was organized as a
square division and trained at
Camp Sherman, Ohio.
World War II The 95th Division was reorganized as a
triangular division for
World War II, and its brigade headquarters were inactivated. The regiment was ordered to active military service on July 15, 1942, and was reorganized at
Camp Swift, Texas. The 377th, 378th, and 379th Infantry Regiments underwent individual soldier and collective unit training at posts in the United States, including
Camp Coxcomb,
California. In August 1944, the 95th Division arrived in
England, and in September it entered combat in France. From the fall of 1944 until the end of the war in April 1945, the regiments of the 95th Division took part in several campaigns, including, Normandy, Northern France, Rhineland, Ardennes-Alsace, and Central Europe. After the war, the 95th Division returned to the United States, and it was inactivated at
Camp Shelby,
Mississippi on October 12, 1945.
Post-World War II On March 14, 1947, the 378th Infantry was reactivated as a unit of the Organized Reserves with its headquarters in
Oklahoma City,
Oklahoma. In 1952, the Organized Reserve Corps was redesignated the United States Army Reserve. On April 1, 1959, the regiment was reorganized and redesignated the 378th Regiment, a unit of the 95th Division (Training). On September 3, 1962, the regiment's headquarters was moved to
Lawton, Oklahoma. On December 30, 1967, the 378th Regiment was reorganized to consist of the 1st, 2nd, and 3rd Battalions, elements of the Army Reserve's 95th Division (Training). On October 1, 1994, the regiment was reorganized as 1st, 2nd, and 3rd Battalions, elements of the Reserve's 95th Division (Institutional Training). A January 13, 1995 reorganization resulted in the 378th Infantry being designated as 3rd Battalion, 378th Regiment, a unit of the 95th Division (Institutional Training). On October 16, 1996, the 378th Infantry was reorganized as 1st, 2nd, and 3nd Battalions, elements of the 95th Division (Institutional Training). Following the attacks of September 11, 2001, units of the 95th Division, including the 378th Regiment were ordered to active military duty as part of the global
war on terrorism. On October 1, 2007, 1st Battalion, 378th Infantry was relieved from assignment to the 95th Division and assigned to the 98th Division (Institutional Training). On September 16, 2008, the 98th Division was redesignated the 98th Training Division. On September 16, 2009, the 95th Division was redesignated as the 95th Training Division. ==Distinctive unit insignia==