procured and put into production in the Soviet Union as the Mark BT, later developed into the famous Soviet T-34 tank. In 1993, experts from the Library of Congress traveled to Moscow to copy previously secret archives of Communist Party USA (CPUSA) records, sent to the Soviet Union for safekeeping by party organizers. The records provide an irrefutable record of Soviet intelligence and cooperation provided by those in the radical left in the United States from the 1920s through the 1940s. Some documents revealed that the CPUSA was actively involved in secretly recruiting party members from African-American groups and rural farm workers. The records contained further evidence that Soviet sympathizers had indeed infiltrated the State Department, beginning in the 1930s. Included were letters from two U.S. ambassadors in Europe to President Franklin D. Roosevelt and a senior State Department official. Thanks to an official in the State department sympathetic to the Party, the confidential correspondence, concerning political and economic matters in Europe, ended up in the hands of Soviet intelligence. In the late 1930s and 1940, Soviet intelligence had multiple staging areas for plots to murder exiled Russian revolutionary Leon Trotsky, then living in Mexico City. Josef Grigulevich, an NKVD agent who had direct orders from Stalin to kill Trotsky, had a safe house in Zook's Drugstore in Santa Fe, New Mexico. The Soviets had two plans to assassinate Trotsky, one involving the Mexican Stalinist David Siqueiros, and the other the Spanish Ramón Mercader. One account of the first, failed raid on Trotsky's home states that Grigulevich tricked Robert Sheldon Harte, an American Communist who was Trotsky's bodyguard, into opening the gate. The Soviets failed to kill Trotsky during this attempt, but betrayed Harte, and they killed him for being a witness. Siqueiros then escaped to Chile with the help of Pablo Neruda. Grigulevich likely then crossed the border north and took refuge at Zook's Pharmacy. The second later attempt by Mercader was successful and Trotsky was murdered in Mexico. Soble spy ring Jacob Albam and the Sobles (Jack and Myra) were indicted on espionage charges by the FBI in 1957; all three were later convicted and served prison terms. Alleged members of their spy ring, the Zlatovskis, remained in Paris, France, where the laws did not allow their extradition to the United States for espionage. Robert Soblen was sentenced to life in prison for his espionage work at Sandia