Captain Macomber was a member of Headquarters Company, 1st Battalion, 19th Infantry Regiment, 24th Infantry Division. He was taken Prisoner of War while fighting the enemy in South Korea on 16 July 1950, forced to march to North Korea on the "Tiger Death March", and died while a prisoner on 31 July 1951 at An-Dong, North Korea. His remains were not recovered. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

For his leadership and valor, Captain Macomber was awarded the Bronze Star Medal with Oak Leaf Cluster, the Purple Heart, the Combat Infantryman's Badge, the Prisoner of War Medal the National Defense Service Medal, the Republic of Korea War Service Medal.