"Beginning in 1947, the House Un-American Activities Committee (HUAC) conducted hearings that attempted to gather information on communist activities in Hollywood. This site has short biographies of the "Hollywood Ten," the first individuals who refused to testify, thereby earning a place on the blacklist. Being blacklisted meant that for many years they were unable to work in Hollywood under their real names. The 10 were Alvah Bessie, Herbert J. Biberman, Lester Cole, Edward Dmytrk, Ring Lardner, Jr., John Howard Lawson, Albert Maltz, Samuel Ornitz, Adrian Scott, and Dalton Trumbo. From Gary Handman, a librarian at the University of California, Berkeley." (from LII)  Also has links to bibliography and other sources.