Despite its appeal to artists and intellectuals during the Great Depression, Algren told McCarrell that he never joined the Communist Party. Among other reasons, he cited negative experiences both he and Richard Wright had with party members. However, his involvement in groups deemed "subversive" during the McCarthy years drew the attention of the Federal Bureau of Investigation (FBI). Among his affiliations, he was a participant in the John Reed Club in the 1930s and later an honorary co-chair of the "Save Ethel and Julius Rosenberg Committee" in Chicago. According to Herbert Mitgang, the FBI suspected Algren's political views and kept a dossier on him amounting to more than 500 pages but identified nothing concretely subversive.