Crawford H. Greenewalt (1902-1993) was an executive with the DuPont Company and president of the firm from 1948 to 1962. He had a passion for the natural sciences, and combined his love of ornithology with photography. He was especially known for his high-speed photographs of hummingbirds. His ornithological interests included bird songs, the radiance of hummingbird feathers, and the evolution of shapes and sizes of birds in relation to their flight abilities. Greenewalt's personal papers are primarily focused on his retirement years and his avocational interests. The papers document Greenewalt's political activities in the Republican National Committee and include exchanges with many of the leading political and business figures of the day. Of particular significance are the papers describing Greenewalt's work in photography and ornithology, beginning in 1948. These materials trace his research interests in the hummingbird and bird flight and his trips to places like Brazil, Peru, Venezuela, the Antilles, New Guinea, and the Galapagos Islands in order to observe and photograph birds in their natural habitats. Other files describe Greenewalt's work on the visiting committee at the Massachusetts Institute of Technology (1965-1987), which evaluated the school's academic programs.

Pierre Gentieu (1842-1930) was an artist, photographer, and an employee of the DuPont Company for thirty-four years. Pierre Gentieu and his wife, Sarah Albina "Binie" Gentieu (1846-1925) had six children. Although three children had no issue, they had nine grandchildren and twenty great grandchildren. All six children worked for the DuPont Co. and several grandchildren did as well. This collection consists of nine albums that document the Gentieu family history, primarily the life of the patriarch of the family Pierre Gentieu (1842-1930). The albums contain originals and reproductions of correspondence, family trees, documents, photographs, and ephemera.