Julius and Ethel Rosenberg Convicted of Espionage in Controversial Red Scare Trial

On March 29, 1951, Julius and Ethel Rosenberg were found guilty of conspiracy to commit espionage after a three-week trial that began on March 6, 1951. The couple had been charged with providing top-secret information about American radar, sonar, jet propulsion engines, and nuclear weapon designs to the Soviet Union. Ethel’s brother, David Greenglass, who had been a machinist at the Manhattan Project laboratory at Los Alamos, New Mexico, served as the chief witness for the prosecution. Assistant U.S. Attorney Roy Cohn led the prosecution. On April 5, Judge Irving Kaufman sentenced the couple to death.

The Rosenbergs’ trial occurred at the height of Cold War hysteria and McCarthyism. During the proceedings, David and Ruth Greenglass provided the only testimony directly linking the Rosenbergs to espionage. Many years later, David Greenglass admitted that he had committed perjury by corroborating his wife’s testimony about Ethel, without which she would most likely not have been convicted. In 2024, the Rosenbergs’ sons were given a copy of a contemporary hand-written memo by NSA codebreaker Meredith Gardner based on Russian decrypts, claiming that Ethel Rosenberg knew about Julius’ espionage work but that “due to ill health she did not engage in the work herself.”

The Rosenberg case became a lightning rod for debates about justice, anti-communism, and government power. A worldwide campaign for mercy failed. On June 19, 1953, Julius Rosenberg was executed at 8:05 p.m. at Sing Sing Prison, followed by Ethel at 8:15 p.m. Ethel’s execution was particularly gruesome—after the normal course of three electric shocks, attendants discovered her heart was still beating, requiring two additional shocks. They became the first American civilians executed for conspiracy to commit espionage and the first to suffer that penalty during peacetime. Ethel became the first woman executed by the U.S. government since Mary Surratt in 1865, demonstrating how Red Scare prosecutions could override evidence, due process, and proportionality.