Constituted 24 June 1921 as 398th Infantry Regiment, allotted to Organized Reserves, assigned to 100th Division, 5th Corps Area, and organized February 1922. Ordered into active military service, less personnel, and organized 15 November 1942 at Fort Jackson, S.C., as element of 100th Infantry Division. Inactivated 29 January 1946 at Camp Kilmer, New Jersey.
Under the provisions (UP) of War Department General Order (WDGO) 103, 1946, all companies of the 1st Battalion are entitled to the Distinguished Unit Citation (DUC) embroidered RAON L'ETAPE.
UP Department of the Army (DA) GO 45, 1952, all companies of the 3d Battalion entitled to DUC embroidered BEILSTEIN.
UP 100th Infantry Division GO 209, 1945, Headquarters Company entitled to Meritorious Unit Citation (MUC) embroidered EUROPEAN THEATER.
Coat of Arms
Shield. Azure, A Kentucky flint-lock rifle in bend with a powderhorn suspended therefrom all or.
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: I am Ready.
The shield is blue for Infantry, and the rifle and powderhorn are representative of the geographic area of the organization.
The insignia is the shield, crest, and motto of the Coat of Arms of the regiment.