Corporal Christiansen was a member of Headquarters and Service Company, 3rd Battalion, 7th Marines, 1st Marine Division. He was Killed in Action while fighting the enemy in Korea on 12 September 1951.

Christiansen was awarded the Purple Heart, the Combat Action Ribbon, the Korean Service Medal, the United Nations Service Medal, the National Defense Service Medal, the Korean Presidential Unit Citation and the Republic of Korea War Service Medal.