Chronological, 1935

The bulk of the collection consists of correspondence, writings by Knopf, and clippings from journals and newspapers created over the course of his entire career, beginning in medical school. The correspondence includes letters from many historical figures, including (but not limited to) Sir William Osler, Robert Koch, Margaret Sanger, Simon Flexner, Andrew Carnegie and John D. Rockfeller. The tuberculosis clippings subseries in Series 6 is arranged alphabetically by author's last name. The bulk of the material is in English, although there are several pieces in other languages, mostly German and French.

The Knopf Papers may be of special interest to those researching the history of tuberculosis and treatment, the history of birth control, and cremation and burial practices. The bulk of the Bruno Heymann correspondence deals with Knopf's efforts from 1934-1935 to bring Heymann from Germany to the United States, and may be of interest to those researching displaced foreign physicians and scholars during this time period. Also of note are two instances where Knopf's authority on tuberculosis was misused. Knopf's was involved in a newspaper slander case in 1907, as well as a dispute over an endorsement of Terpezone, a tuberculosis treatment, in 1933.