The collection consists of Dugan's articles, correspondence, lecture notes, material for his astronomy classes at Princeton, and printed matter. The collection contains typescripts of articles, course outlines and final examinations, and copies of biographies of astronomers written for reference books, such as the Dictionary of American Biography. There is correspondence with publishers, academic colleagues, scholarly journals, astronomical societies, and directors of observatories, including ones at Harvard (Harlow Shapley) and the University of Arizona, as well as some personal correspondence. The collection also contains reports by Dugan to members of Commission 27 (Commission des Etoiles Variables) of the International Astronomical Union.