Ruth Printz, the eldest of four children, was born in New York City on 30th April 1924. She was educated at Seward Park High School. After leaving school she became a typist.
Ruth joined the Young Communist League (YCL). She married David Greenglass, a fellow member of the YCL, in 1942. Later the couple had two children.
During the Second World War her husband joined the United States Army. Promoted to the rank of sergeant, he was transferred to Los Alamos, where attempts were being made to develop the atom bomb.
In 1945 David Greenglass left the army and open a small machine shop in Manhattan with his brother-in-law, Julius Rosenberg. However, the business did badly and Greenglass left the partnership.
On 5th September 1945, Igor Gouzenko, a KGB intelligence officer based in Canada, defected to the West claiming he had evidence of an Soviet spy ring based in Britain. Gouzenko provided evidence that led to the arrest of 22 local agents and 15 Soviet spies in Canada. Some of this information from Gouzenko resulted in Klaus Fuchs being interviewed by MI5. Fuchs denied any involvement in espionage and the intelligence services did not have enough evidence to have him arrested and charged with spying. However, after repeated interviews with Jim Skardon he eventually confessed on 23rd January 1950 to passing information to the Soviet Union . Six weeks later Fuchs was sentenced to 14 years in prison.
In June 1950 the FBI arrested Harry Gold, who confessed to helping Klaus Fuchs in his espionage activities in the United States. He named