Cold War: The trial of Ethel and Julius Rosenberg begins.

The Cold War was a period of global geopolitical rivalry between the United States (US) and the Soviet Union (USSR) and their respective allies, the capitalist Western Bloc and communist Eastern Bloc, which began in the aftermath of the Second World War and ended with the dissolution of the Soviet Union in 1991. The term cold war is used because there was no direct fighting between the two superpowers, though each supported opposing sides in regional conflicts known as proxy wars. In addition to the struggle for ideological and economic influence and an arms race in both conventional and nuclear weapons, the Cold War was expressed through technological rivalries such as the Space Race, espionage, propaganda campaigns, embargoes, and sports diplomacy.

Julius Rosenberg and Ethel Rosenberg were an American married couple who were convicted of spying for the Soviet Union, including providing top-secret information about American radar, sonar, jet propulsion engines, and nuclear weapon designs. Convicted of espionage in 1951, they were executed by the federal government of the United States in 1953 using New York's state execution chamber in Sing Sing in Ossining, New York, becoming the first American civilians to be executed for such charges and the first to be executed during peacetime. Other convicted co-conspirators were sentenced to prison, including Ethel's brother, David Greenglass, Harry Gold, and Morton Sobell. Klaus Fuchs, a German scientist working at the Los Alamos Laboratory, was convicted in the United Kingdom. For decades, many people, including the Rosenbergs' sons, have maintained that Ethel was innocent of spying and have sought an exoneration on her behalf from multiple U.S. presidents.