[5] It moved to Camp Malakole on 27 January 1941 and was assigned to the air defense of Pearl Harbor[3] It was engaged during the attack on Pearl Harbor on 7 December 1941; three members of the regiment (Sergeants Henry Blackwell, Jr., and Warren D. Rasmussen, and Corporal Clyde C. Brown) were killed when the two rented Piper Cub aircraft they were taking on a sightseeing trip were shot down by incoming Japanese planes.

[7] The 951st Antiaircraft Artillery Automatic Weapons Battalion moved to the Philippines on 9 January 1945, returned to San Francisco for inactivation 26 December 1945.

[8] The 251st Antiaircraft Artillery Group departed Bougainville on 11 December 1944, stopped at Lae, New Guinea and Manus, Admiralty Islands, arriving at Lingayen Gulf, Philippines on 9 January 1945.

[6] A Gold color metal and enamel device 1+1⁄8 inches (2.9 cm) in height overall consisting of a shield blazoned: Or, six pallets couped Gules, a ship of Cabrillo’s time Argent; on a canton Azure a fleur-de-lis encircled by a garland of laurel of the first.

The six pallets couped produce a diminished bordure effect on the shield and represent the six batteries comprising the Regiment at the time of its organization.

[12] World War II 251st CA (AA): Central Pacific and Northern Solomons[5] 251st AAA Group: Luzon, Philippines[9]