Private First Class Dunn was a member of Company E, 2nd Battalion, 7th Cavalry Regiment, 1st Cavalry Division. He was Killed in Action while fighting the enemy in South Korea on 22 August 1950.

Dunn was awarded the Purple Heart, the Combat Infantryman Badge, 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.