Gold was a chemist from Philadelphia who had been a courier between Klaus Fuchs, (a British scientist who was stealing atomic bomb information), and the Soviets. Gold’s confession led to the arrest of David Greenglass, who was employed at Los Alamos where the Manhattan Project was being developed. Greenglass implicated his sister and brother-in-law, Julius and Ethel Rosenberg, telling officials they were actively spying for the Soviets.
Harry Gold was paroled in 1965 after serving about half of his sentence. He died in 1972.