Private First Class Robertson was a member of the 2nd Battalion, 1st Marines, 1st Marine Division. He was seriously wounded while attacking enemy positions near Seoul, South Korea and died of those wounds on 18 September 1950.

PFC Robertson 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.