The effectiveness of these fixed gun emplacements was debated for many years, and test firings were extremely unpopular with nearby residents, the concussion shattering windows in buildings and houses for miles around.

In World War II, Fort MacArthur had a Harbor Entrance Command Post and a Harbor Defense Command Post for US seacoast defense of shipbuilding factories (e.g., CalShip, Todd Pacific), "giant aircraft factories"[2] (Douglas, Hughes, Martin, Northrop), the Huntington Beach Oil Field, and the San Pedro Bay harbor (Port of Los Angeles & Port of Long Beach) which made the Los Angeles metropolitan area a target for attack.

[3][4] The DC had High Frequency Crosstell communication with the 1959–1966 Semi-Automatic Ground Environment (SAGE) Master Direction Center at Norton Air Force Base (DC-17) for coordinating Army intercepts of targets penetrating through the larger USAF Los Angeles Air Defense Sector defended by fighter aircraft.

[7] The Fort MacArthur Direction Center (DC) began in 1960 with an AN/FSG-1 computer that was the last of 10 installed and which replaced an Interim Battery Data Link (IBDL).

The Army dedicated the DC's Missile Master bunker with an Antiaircraft Operations Center ("Blue Room") on December 14, 1960, prior to the USAF/FAA ARSR-1C radar opening in 1961 at San Pedro Hill Air Force Station.

[8] [9][5] Fort MacArthur's 47th Artillery Brigade operated the DC,[10] and the vacuum tube AN/FSG-1 was replaced on January 31, 1967, with a solid-state Hughes AN/TSQ-51 Air Defense Command and Coordination System.

The Battle of Los Angeles and Fort MacArthur Museum are featured in California's Gold episode 6005 with Huell Howser.

NCIS: Origins is filmed on a 1990s era recreated set of Camp Pendleton, built at Fort MacArthur.