Private First Class Lenon was a member of Company E, 2nd Battalion, 7th Marines, 1st Marine Division. He was Killed in Action while fighting the enemy near the Chosen Reservoir, North Korea on 27 November 1950. His remains were not recovered. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

Lenon 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.