In addition to his civil rights activism during the 1960s and 1970s, Sanders was active in several peace and antiwar movements while attending the University of Chicago, becoming a member of the Student Peace Union. He applied for conscientious objector status during the Vietnam War; his application was eventually turned down, by which point he was too old to be drafted. Although he opposed the war, Sanders never criticized those who fought in it, and he has long been a strong supporter of veterans' benefits. He also was briefly an organizer with the United Packinghouse Workers of America while in Chicago. He also worked on the reelection campaign of Leon Despres, a prominent Chicago alderman who was opposed to mayor Richard J. Daley's Democratic Party machine. Throughout his student years, Sanders read the works of many political authors, from Thomas Jefferson, Abraham Lincoln, and John Dewey to Karl Marx and Erich Fromm.