Roy Franklin Nichols (1896-1973) completed his doctorate at Columbia in 1923 and taught there briefly before joining the faculty of the University of Pennsylvania, where he served as professor of history and dean of the graduate school until his retirement in 1966. Among his many works, he was best known for The Disruption of American Democracy, a study of the causes of the Civil War, which won the Pulitzer Prize in 1949. Nichols served as president of the American Historical Association in 1966.