Private First Class Harrington was a veteran of World War II. In Korea, he was a member of Company C, 1st Battalion, 19th Infantry Regiment, 24th Infantry Division. He was taken Prisoner of War while fighting the enemy in South Korea on 16 July 1950, forced to march to North Korea on the "Tiger Death March" and died while a prisoner at Manpo, North Korea, on 4 October 1950. His remains were not recovered. His name is inscribed on the Courts of the Missing at the Honolulu Memorial.

Harrington was awarded the Purple Heart, the Combat Infantryman's Badge with Star, the Prisoner of War Medal, the Korean Service Medal, the United Nations Service Medal, the National Defense Service Medal, the Korean Presidential Unit Citation, the Republic of Korea War Service Medal, the European-African-Middle Eastern Campaign Medal with 4 Stars, the Arrowhead for D-Day participation and the World War II Victory Medal.