First Lieutenant Sealy was a member of Company F, 2nd Battalion, 7th Infantry Regiment, 3rd Infantry Division. He was Killed in Action while fighting the enemy in North Korea on 3 December 1950. His remains were not recovered. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

Sealy 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.