The harshness of the sentence was unprecedented. David Greenglass, who was the actual source of the atomic secrets, was sentenced to 15 years in prison. He had been led to expect a sentence of five years when he initially agreed to co-operate with the prosecution. Given the severity of the Rosenberg sentence, however, it was felt that a five-year term would be seen as too lenient.
The date of execution was stayed until the appeals process could run its course. The Second Circuit Court of Appeals upheld the verdict, on 10 January 1952, and the United States Supreme Court refused to hear the case in September 1953.
The Communist Party of the United States formed the ‘National Committee to Secure Justice in the Rosenberg Case’, and the Rosenbergs pinned their hopes on a reversal, in the face of widespread public support, but they were disappointed. Their execution date was set for 17 June 1953, and the Supreme Court refused a petition for a stay of execution. President Eisenhower was petitioned for clemency but he too refused to intervene.
On 16 June, just a day before the execution was due to take place, a legal motion was filed, claiming that the Rosenbergs should have been tried under the Atomic Secrets Act 1946, which superseded the Espionage Act of 1917. The 1946 Act stipulated that a jury should pass the sentence, not the judge, as had occurred with the Rosenbergs. This legal challenge should have provided them a further stay of sentence of at least six months, while the case was heard, but the Chief Justice decided to hear the case immediately, and the court ruled that, as both laws were still in force, the use of the 1917 was legally permissible, and the stay of execution was lifted.
The Rosenbergs were scheduled to be executed at 11 pm on Friday 19 June 1953. Yet again, a plea for presidential clemency was refused. In a last desperate effort, their defence lawyer asked that the sentence again be delayed, as sunset marked the start of the Jewish Sabbath. To his horror, instead of delaying the execution, the schedule was moved forward to 8 pm, to avoid the Sabbath, and the last hope of delay was finally extinguished.
Julius Rosenberg was electrocuted first, at 8 pm, Ethel Rosenberg followed, and was still alive after the first attempt. As a result of her small stature, the electrodes fitted poorly, in a chair designed for larger male occupants, and she required two further charges of electricity to kill her.
There seems little doubt that Julius Rosenberg did engage in the transfer of secrets from the US to the Communists, but the true role of Ethel Rosenberg in the affair has always been questioned.
In 2000, David Greenglass claimed he had committed perjury, falsely implicating his sister in order to satisfy the authorities, who wanted Ethel implicated so that she could be used as an emotional lever against Julius, to induce him to confess and name his conspirators. There appears little doubt that the authorities manipulated the evidence against Ethel to coerce Julius to confess, a plan that failed abjectly, both during and after the trial, since neither Julius nor Ethel implicated anyone else.
The irony of their case is that the information they acquired and passed on was of little real use in the development of atomic weapons. The Rosenbergs were, to a certain extent, victims of the political climate that pervaded the United States at the time.
Other spies tried since, on far more serious charges of treason and espionage, have generally received far more lenient sentences.