World, a Communist Party organ, and he testified in 1954, "I was associated with the communist movement." From 1937 to 1942, Oppenheimer was a member at Berkeley of what he called a "discussion group", which was later identified by fellow members Haakon Chevalier and Gordon Griffiths as a "closed" (secret) unit of the Communist Party for Berkeley faculty. The FBI opened a file on Oppenheimer in March 1941. It recorded that he attended a meeting in December 1940 at Chevalier's home that was also attended by the Communist Party's California state secretary, William Schneiderman, and its treasurer, Isaac Folkoff. The FBI noted that Oppenheimer was on the Executive Committee of the American Civil Liberties Union, which it considered a communist front organization. Shortly thereafter, the FBI added Oppenheimer to its Custodial Detention Index, for arrest in case of national emergency. Debates over Oppenheimer's party membership or lack thereof have turned on very fine points; almost all historians agree he had strong left-wing views during this time and interacted with party members, though there is considerable dispute over whether he was officially a member of the party. At his 1954 security clearance hearings, he denied being a member of the Communist Party but identified himself as a fellow traveler, which he defined as someone who agrees with many of the goals of communism but is not willing to blindly follow orders from any Communist Party apparatus. Throughout the development of the atomic bomb, Oppenheimer was under investigation by both the FBI and the Manhattan Project's internal security arm for left-wing associations he was known to have had in the past. He was followed by Army security agents during a trip to California in June 1943 to visit his former girlfriend, Jean Tatlock, who was suffering from depression. Oppenheimer spent the night in her apartment. Tatlock committed suicide on January 4, 1944, leaving Oppenheimer deeply grieved. In August 1943, he volunteered to Manhattan Project security agents that George Eltenton, whom he did not know, had solicited three men at Los Alamos for nuclear secrets on behalf of the Soviet Union. When pressed on the issue in later interviews, Oppenheimer admitted that the only person who had approached him was his friend Haakon Chevalier, a Berkeley professor of French literature, who had mentioned the matter privately at a dinner at Oppenheimer's house. Brigadier General Leslie R. Groves, Jr., the director of the Manhattan