Two trials of Alger Hiss on two counts of perjury in 1949-1950. In August 1948 HUAC hearings, Whittaker Chambers accused Hiss of belonging to the Communist underground in Washington, D.C. in the 1930s. Hiss denied the charges and, on September 27, 1948, filed a libel suit against Chambers.
In the course of pre-trial depositions in Baltimore, MD, Chambers produced what would become known as the Baltimore documents. On December 2, 1948, he produced what became known as the Pumpkin Papers. This physical evidence shifted the argument in the case from the issue of whether Hiss had been a Communist in the 1930s, and whether he had known Chambers longer and better than he admitted, to the question of whether Hiss had committed espionage. However, due to the statute of limitations, Hiss could not be prosecuted on espionage charges. Therefore, on December 15, 1948, a federal grand jury in New York indicted him on two counts of perjury: first, that he was lying when he testified before the grand jury that he had never given any documents to Whittaker Chambers; and, second, that he was lying when he claimed he had never seen Chambers after January 1, 1937.
The first perjury trial opened on May 31, 1949 and ended on July 8, 1949 with a hung jury. The second trial began on November 17, 1949 and ended on January 21, 1950 with a guilty verdict. Hiss was sentenced to five years of imprisonment and served 44 months in the Lewisburg Penitentiary in Pennsylvania.