Capt. Martin Gelb of Derry was part of the Office of Strategic Services, the precursor to the Central Intelligence Agency.
He served in England, France and Germany on missions that included supporting U.S. and British operations during the D-Day invasion and assisting with the liberation of the Buchenwald concentration camp.
U.S. Sen. Jeanne Shaheen presented Gelb with a bronze replica of the Congressional Gold Medal on Monday in Derry.
She said only about 100 of Gelb’s fellow officers are still living and called him a true American hero.
Gelb says he was overwhelmed by the attention, which he called unbelievable.