The 121st Field Artillery Battalion, as designated on February 1, 1942, distinguished itself in the Pacific Theatre of Operations. Its honors were: Aitape, Biak, Leyte, Luzon and New Guinea (with Saidor Arrowhead). Early in 1943 the 121st Field Artillery Battalion was issued 75 mm howitzers in place of the 155 mm howitzers that were its normal weapons as the general support battalion of Division Artillery.