Sergeant Blackmon was a member of Company G, 3rd Battalion, 5th Marines, 1st Provisional Marine Brigade. He was seriously wounded while fighting the enemy near Kosomg, South Korea, and died of those wounds on 7 August 1950.

Blackmon 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.