Crawford H. Greenewalt (1902-1993) was an executive with the DuPont Company and president of the firm from 1948 to 1962. In 1942, when the DuPont Company agreed to participate in the Manhattan Project, Greenewalt was named chief liaison, working with the physicists at the University of Chicago Metallurgical Laboratory, including Arthur Compton (1892-1962) and Enrico Fermi (1901-1954), who were developing techniques for plutonium separation. The collection consists of eight volumes of Greenewalt's diaries, which describe the history of the Manhattan Project and the development of the United States' first atomic bombs that were used to end the Second World War. The diaries describe the technical history of the project, as well as the relationships that developed between scientists.

George Y. Swickard (1906-1958) was a medical doctor involved in industrial medicine who worked with E.I. du Pont de Nemours & Company. During World War II, Swickard worked as a medical supervisor with the DuPont Company at various locations, including atomic research projects at Oak Ridge, Tennessee, and at Hanford, Washington. This collection consists of certificates, newsletters, pamphlets, and souvenir programs amassed by Swickard, mostly in the course of his work for DuPont.

Richard Douglas Caney (1918-1994) was a chemical engineer with E.I. du Pont de Nemours & Company, working in the Explosives Department on the Manhattan Project. To remember his participation in the Manhattan Project, Caney prepared a scapbook of newspaper clippings of articles that flooded the media after the atomic bombs were dropped and the secrecy around the project ended.