World War II

Following the devastating surprise attack on Pearl Harbor, the threat of Japanese naval incursions, amphibious invasions, and carrier-borne air raids necessitated an immediate reinforcement of the Pacific defenses. In response, the unit was reactivated on April 21, 1942, as the 41st Coast Artillery at Fort Hase in the Territory of Hawaii. Operating under the Army's Hawaiian Department, the regiment was charged with safeguarding the strategic island chain during the most volatile and high-alert years of the Pacific War.

Throughout their wartime service, the soldiers of the 41st Coast Artillery manned massive harbor defense guns, monitored radar installations, and maintained constant combat readiness to repel potential enemy forces. The units were dispersed across critical geographical choke points, ensuring that vital naval lanes and military airfields remained shielded from hostile reconnaissance or bombardment. Their presence allowed Pearl Harbor to safely recover and serve as the main staging ground for the U.S. Pacific Fleet.

While the rapid advance of Allied forces across the Pacific eventually pushed the front lines far west of Hawaii, the brigade's defensive vigilance remained crucial for protecting essential logistics and communications hubs. The soldiers endured rigorous live-fire training cycles and coordinated with naval forces to refine combined-arms coastal defense tactics. This preparation ensured that any secondary Japanese offensive directed at the Hawaiian mainland would face an impenetrable wall of heavy artillery fire.

The regiment served honorably on active duty in the Hawaiian Department until May 25, 1944, when the direct threat of invasion had officially subsided. At that point, the unit was retired from the active rolls of the regular Army and its personnel reallocated to meet the demands of offensive campaigns in the Western Pacific. For its vital contributions to safeguarding the Hawaiian islands during a time of extreme peril, the unit was awarded the Asiatic-Pacific Campaign Streamer.