Scope and Contents From the Collection: The collection reflects his career activities and his research. The largest part of Dr. Mahan's materials consist of his subject files, which cover all aspects of his life and career. The other series are more specific to the various phases of his life. The ISAC series also contains a subject file and there is some overlap with the first subject file. The papers include correspondence, copies of articles or excerpts from longer secondary works, notes extracted from primary sources, tapes...