Answer:
Julius Rosenberg and Ethel Rosenberg (née Greenglass) were American citizens who were convicted of spying on behalf of the Soviet Union. The couple were accused of providing top-secret information about radar, sonar, jet propulsion engines and valuable nuclear weapon designs (at that time the United States was the only country in the world with nuclear weapons). Convicted of espionage in 1951, they were executed by the federal government of the United States in 1953 in the Sing Sing correctional facility in Ossining, New York, becoming the first American civilians to be executed for such charges and the first to suffer that penalty during peacetime.
Other convicted co-conspirators were sentenced to prison, including Ethel's brother, David Greenglass (who had made a plea agreement), Harry Gold, and Morton Sobell. Klaus Fuchs, a German scientist working in Los Alamos, was convicted in the United Kingdom.[5][6]
For decades, the Rosenbergs' sons (Michael and Robert Meeropol) and many other defenders maintained that Julius and Ethel were innocent of spying on their country and were victims of Cold War paranoia. After the fall of the Soviet Union, much information concerning them was declassified, including a trove of decoded Soviet cables (code-name: Venona), which detailed Julius's role as a courier and recruiter for the Soviets. Ethel's role was as an accessory who helped recruit her brother David into the spy ring and who worked in a secretarial manner typing up documents for her husband that were then given to the Soviets. In 2008, the National Archives of the United States published most of the grand jury testimony related to the prosecution of the Rosenbergs.
