Battery “A” 121st Field Artillery Regiment was mobilized for WWII on October 15, 1940. The Battery and many of its Soldiers were from Milwaukee, Wisconsin. In February 1942 the 121st Field Artillery Regiment was re-organized and Battery “A” would ultimately become Battery “A”, 121st Field Artillery Battalion. The 121st Field Artillery Battalion arrived in the Pacific Theatre with the 32nd Infantry Division in May of 1942. The unit demobilized on February 28th, 1946 while in Japan.