Bill Mackey (1906-1996) was a chemical engineer and the plant manager of the Technical Division of the Explosives Department of the E.I. du Pont de Nemours & Company. His papers consist of a mix of personal and DuPont Company materials documenting his career as an explosives expert.

Pierre Samuel "P.S." du Pont (1870-1954) was president of E.I. du Pont de Nemours & Co. (more commonly known as the DuPont Company or simply DuPont) from 1915 to 1919 and chairman of the board from 1919 to 1940. P.S. du Pont was the great grandson of Eleuthere Irenee du Pont (1771-1834), founder of E.I. du Pont de Nemours & Company. He was also an avid collector of documents on the early history of the du Pont family and the DuPont Company. This collection contains elements which were selected from both company and family papers. The material was lodged in du Pont's Wilmington office for a number of years prior to his death in 1954.