Cold War: A Brief History
Ethel and Julius Rosenberg
Julius and Ethel Rosenberg, convicted of passing nuclear weapons secrets to the Soviet Union, were the first American civilians executed for espionage. Ethel's brother, David Greenglass, was an employee of the Los Alamos atomic bomb project. He passed secrets to Julius and Ethel, who then funneled them to the Soviets. They were executed in the electric chair on June 19, 1953.