251st Air Defense Artillery Regiment

The 251st Coast Artillery was a coast artillery regiment in the California National Guard.

Lineage
Constituted 1 November 1924 in the California National Guard as the 251st Coast Artillery (HD)(Coast Artillery Corps) as follows- Redesignated 251st Coast Artillery (AA) 1 January 1930.
 * HHB from ?
 * 1st Battalion HHB from new
 * A Battery from E Battery 250th Coast Artillery
 * B Battery from F Battery 250th Coast Artillery
 * C Battery from H Battery 250th Coast Artillery
 * D Battery from new
 * 2nd Battalion from new
 * inducted into Federal service 16 September 1940 at home stations
 * 3rd battalion constituted 27 May 1942 at Nadi, Fiji Islands

Arrival of the regiment in Fiji was reported on 1 June 1942, 'more than doubling the anti-aircraft defences of Fiji.'

Regiment broken up 1 March 1944 as follows-
 * HHB as HHB 251st Antiaircraft Artillery Group

The individual battalions were also broken up and redesignated.
 * 1st Battalion as 746th Antiaircraft Artillery Gun Battalion
 * 2nd battalion as 951st Antiaircraft Artillery Automatic Weapons Battalion
 * 3rd Battalion as 140th Antiaircraft Artillery Battalion

746th Antiaircraft Artillery Gun Battalion inactivated 15 January 1946 at Camp Stoneman, California.

Later the regiment became an air defense regiment, and was equipped with the Nike-Hercules missile. Elements which were to become part of the 251st Air Defense Artillery were under control of the Regular Army's 47th Artillery Brigade (Air Defense), part of Army Air Defense Command. The brigade's command post was at the Fort MacArthur Direction Center. In May 1959, the 720th ADA Battalion was redesigned as the 4th Missile Battalion (Nike-Hercules) 251st Artillery, California Army National Guard.

Distinctive unit insignia
A Gold color metal and enamel device 1+1/8 in 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. Attached below and to the sides of the shield a Red scroll inscribed “WE AIM TO HIT” in Gold letters. The shield is red for Artillery. 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. The ship is a representation of the ship of Don Juan Rodrigues Cabrillo, a Portuguese, who discovered San Diego Harbor. The charges on the canton, the fleur-de-lis encircled by a garland of laurel, are taken from the coat of arms of the 250th Coast Artillery, as Batter B of the 251st Coast Artillery, California National Guard, is a descendant of Batter F of the 250th Coast Artillery, California National Guard which served during World War I as B Battery of the 65th Coast Artillery (US). The distinctive unit insignia was originally approved for the 251st Coast Artillery (Harbor Defense) on 9 January 1928. It was amended to add the motto on 16 June 1928. It was redesignated for the 746th Antiaircraft Artillery Gun Battalion on 7 January 1952. The insignia was redesignated for the 251st Artillery Regiment on 16 February 1961. It was redesignated for the 251st Air Defense Artillery Regiment on 10 July 1972.
 * Description
 * Symbolism
 * Background