Friedrich (Frederick) Hacker was a distinguished psychiatrist, psychoanalyst, and cultural figure. Born in Vienna in 1914, Hacker left Austria soon after the Anschluss and made his way to Los Angeles via New York and Topeka, Kansas. In Los Angeles, Hacker founded the Hacker Clinic in Beverly Hills (1945) where he treated numerous Hollywood filmmakers and actors and where he socialized with other well-known members of the German-speaking émigré community. Hacker went on to become a specialist in juvenile delinquency and testified before the Senate in 1955 about the influence of television and film on youth. He later studied the psychology of terror and terrorism, appeared as an expert witness in the Sharon Tate murder trial, consulted with Patty Hearst's family after her kidnapping, and worked with West German officials after the Munich attacks in 1972. Hacker's papers include material relating to his diagnosis of Klaus Mann, the son of Thomas Mann, and his fulsome correspondence with Theodor W. Adorno and Max Horkheimer, with whom he worked on understanding the psychology of the fascist subject in the 1940s. The collection also contains letters with Anna Freud, Arthur Koestler, George McGovern, and other important political and cultural figures. Hacker taught psychology classes at the University of Southern California (USC) and lectured to the USC community through the Max Kade Institute in the 1980s. In addition to correspondence, the collection contains many subject files and research documents relating to Hacker's professional and scholarly work.