On 16 February 1942, 3/1 was re-activated at New River, North Carolina. In July 1942, they deployed to Wellington, New Zealand and participated in the following World War II campaigns: Guadalcanal, Eastern New Guinea, New Britain, Peleliu and Okinawa. Beginning in April 1946, they participated in the occupation of North China. The battalion was again deactivated on 20 March 1947 as part of the post-war drawdown of forces.