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.

Colonel Franklin T. Matthias (1908-1993) was commanding officer and area engineer of the Hanford Engineer Works of the Manhattan Engineer District. These are Colonel Matthias's personal papers documenting his work on the Manhattan Project. They include original declassified documents from Hanford and a variety of newspaper clippings and magazine articles collected by Matthias between the time he left Hanford to his death, reflecting his continuing interest in the Manhattan Project and nuclear power.

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.

Gilbert P. Church (1910-1993) was a civil engineer and the field project manager for E.I. du Pont de Nemours & Company at the Hanford Site during the Manhattan Project. His papers relate to the construction by DuPont for the United States government of the Hanford Engineer Works plutonium plant near Pasco, Washington.

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.

Watson C. Warriner Sr. (1917-2015) was a chemical engineer with E.I. du Pont de Nemours & Company during World War II. He worked on the Manahatten Project. This item is a typescript of a personal memoir of Warriner's work at the Hanford Engineer Works and the DuPont Works in connection with the Manhattan Project, including maps and photographs.