In 1939, the New Mexico National Guard was called to active duty for a one-year training period that became the prelude to some of the earliest combat experienced by American troops in World War II.
In 1940, the 111th Cavalry was re-designated the 200th Coast Artillery Regiment and the 158th was reorganized as the 104th Anti-Tank Battalion. On Jan. 6, 1940, these units, along with the 120th Engineer Regiment, were called to active duty.
This included the defense of the Philippines with its infamous Bataan Death March in the Pacific and the invasions of North Africa and Italy in the Mediterranean.
The development of radio proximity-fused artillery shells, together with the subsequent development of the atomic bomb, established New Mexico as a critical partner in the emerging relationship between science and the military that would grow in the decades to follow.