Justice Chambers was a lawyer and a Major in the Marine Corps Reserve when his battalion was called up in 1940. Serving first with the 1st Marine Raider Battalion, the then Lieutenant Colonel Chambers was awarded a Silver Star for evacuating wounded and coordinating the overnight defense of a battalion aid station on Tulagi, where he was one of the wounded himself. Chambers was awarded the Legion of Merit with a Combat V for his leadership of Marines through the Roi-Namur, Saipan, and Tinian campaigns.
Commanding the 3rd Battalion, 25th Marines, Chambers landed on Iwo Jima on February 19, 1945. Landing beneath high ground where dug-in enemy troops could rake the whole beach with fire, Chambers’ unit was tasked with capturing the high ground. On D-Day alone the 3rd Battalion lost over half of its officers and men, but with Chambers’ excellent leadership and combat experience, they secured the high ground. On February 22, Chambers was hit by enemy machinegun fire. He survived his wounds, but could not return to combat. For his exemplary leadership on Iwo Jima, Chambers was initially awarded the Navy Cross. The original recommendation was later reviewed, and the award was upgraded to the Medal of Honor.