Corporal Alcantar was a member of Company L, 3rd Battalion, 224th Infantry Regiment, 40th Infantry Division. He was Killed in Action while fighting the enemy at the "Punchbowl" in North Korea on 29 June 1953.

Alcantar was awarded the Purple Heart, the Combat Infantryman's 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.