Harry J. Haon II (1901-1989) and his son Harry J. Haon III (1934-2013) were chemists and lifetime employees of E.I. du Pont de Nemours & Company, and both came to specialize in sales and marketing. The Harry J. Haon family papers are a collection of correspondence, meeting notes/minutes, drawings/maps, journal articles, DuPont publications, papers expressing once classified information about DuPont products, as well as teaching materials for employees who were novice marketing managers, sales personnel and employees in leadership positions. The collection is composed of two series consisting of the papers of Harry J. Haon, II and Harry J. Haon, III. The careers in DuPont of both Haons are well documented.