Joris Ivens came from the Netherlands, alongside the "Contemporary Historians", the United States John Dos Passos, Archibald MacLeish, Clifford Odets, Lillian Hellman, Herman Shumlin and Ernest Hemingway, the latter largely independently, while all remaining in contact with the Communist Party USA or one of their communist front organizations. In 1931, during his time with Mezhrabpomfilm Otto Katz, Ivens had become acquainted with the Machtergreifung in Hollywood through his lectures Anti-fascist and the Comintern took a footing there. A report of the Special Committee on Un-American Activities of the United States House of Representatives published a four-pronged definition of a "Communist front" in March 1944. Frequently repeated in official government documents, this definition asserted that Communist fronts shared (1) a common origin; (2) organization upon a "Communist pattern"; (3) interlocking personnel; and (4) methods intended to deceive the public. Historian Bernard K. Johnpoll states: Thousands of Americans joined Communist fronts during the 1930s. Few of them realized the true nature of the organizations they joined. The fronts paraded as independent, nonpartisan groups under the facade of non-Communist control. They were actually satellites of the Communist Party whose primary aim was to create the impression of mass support for an essential part of the party line. To maintain the illusion of non- Communist control, the formal leadership of these organizations was almost invariably composed of non-party members; the actual control was, however, in the hands of party activists. In the late 1940s, at the start of the Cold War, the House Committee on Un-American Activities (HUAC) and the Senate Internal Security Subcommittee (SISS) investigated and listed a number of suspected organizations. In 1955, SSIS published a list of what it described as the 82 most active and typical sponsors of Communist fronts in the United States; some of those named had literally dozens of affiliations with groups that had either been cited as Communist fronts or had been labelled "subversive" by either the Subcommittee or the House Committee on Un-American Activities. Schrecker says that anti-Communist leaders believed that the Party used front groups to attract "fellow travelers," who were "unsuspecting liberals and well-meaning dupes drawn into the Communist orbit without realizing that the Party was using them for its own purposes." Schrecker says that on the contrary, "most of these people knowingly collaborated with the party, believing it to be the most effective ally they could find."