The papers consist of correspondence, university-related materials, and laboratory notebooks and manuscripts. The correspondence ranges in dates from 1936 to 1970, with the greatest concentration being in the forties and fifties. The correspondence is business-related, and written to colleagues and associates.

Several manuscripts written by Fennell are also in the collection, written between the mid-forties and mid-sixties. There are also numerous published articles, some written by Fennell, but most written (in German) by others. There are also several class syllabi and laboratory schedules from classes taught by Fennell in the late sixties as well as examinations from those classes. Lecture notes from 1968 are also present, as are laboratory equipment lists and inventories, and other university-related materials. There are also drafts of several speeches and addresses Fennell gave, mostly in the 1930s and 1940s, over WKAR radio. Finally, there are two laboratory notebooks, probably compiled by Fennell during his collegiate career.