The Papers comprise one and one-half boxes and span the period 1897-1983. The bulk of the material dates from the period 1929-1982. The Papers include biographical material, newspaper clippings, correspondence and other material pertaining to Riba's military service in World War's I and II, correspondence and clippings concerning his 1954 African safari, personal and professional correspondence, lectures, reprints, and acknowledgements of contributions to the Riba Fellowship in Urology at the Northwestern Memorial Hospital.
Included in the biographical material are vita, memoirs, personal information questionnaires, and obituaries. Among Riba's military service records are the results of physical examinations, commissions, orders, correspondence, and discharge papers pertaining primarily to his service in the Army Medical Corps during World War II. Of interest is Riba's pilot's book from his service in the Air Corps in World War I. Included are the records of his flight training.
Among the correspondence are photocopies of personal letters from Adali E. Stevenson, whom Riba treated during his governoship. Also included is a small amount of personal and professional correspondence dating from prior to Riba's retirement in 1973 and one folder of correspondence pertaining to his post-retirement activities. Also included is one folder containing letters of condolence received by Riba's family at the time of his death in 1982. Included with the fifty-one reprints of Riba's articles on urology is a complete bibliography of his publications. In addition, the Papers include one folder of the licenses, certificates and diplomas of Riba's younger brother, Gerhardt,a dentist.