Constituted 24 June 1921 as 398th Infantry Regiment, allotted to Organized Reserves, assigned to 100th Division, 5th Corps Area, and organized December 1921. Ordered into active military service, less personnel, and organized 15 November 1942 at Fort Jackson, S.C., as element of 100th Infantry Division. Inactivated 8 January 1946 at Camp Kilmer, New Jersey.
Under the provisions of (UP) War Department General Order (WD GO) 11, 1946, all companies of the 3d Battalion are entitled to the Distinguished Unit Citation (DUC) embroidered HEILBRONN.
UP WD GO 27, 1945, all companies of the 3d Battalion entitled to DUC embroidered BITCHE.
UP 100th Infantry Division GO 142, 1945, Headquarters Company entitled to Meritorious Unit Citation (MUC) embroidered EUROPEAN THEATER.
UP 100th Infantry Division GO 59, 1945, Service Company entitled to MUC embroidered EUROPEAN THEATER.
Coat of Arms
Shield. Azure, a bend wavy argent, to base a "Diamond Rattler" gliding bendwise proper.
Crest. That for the regiments and separate battalions of the Army Reserve: On a wreath of the colors (argent and azure) the Lexington Minuteman proper. The statue of the Minute Man, Captain John Parker (H.H. Kiston, sculptor), stands on the Common in Lexington, Massachusetts.
Motto: On the Alert.
The shield is blue for Infantry. The bend wavy represents the Kanawha River, the general district to which the organization is allocated, and the "Diamond Rattler" refers to the title given to military organizations in the State of West Virginia.
The insignia is the shield, crest, and motto of the Coat of Arms of the regiment.