John W. Macklem (1867-1948) was a collector of E.I. du Pont de Nemours photographs. He authored one book, Sixty years of DuPont Lodge, No. 29, ancient free and accepted Masons, 1876-1936 (Wilmington, Delaware; The Lodge (?): 1939)

Pierre A. Gentieu (1842-1930) was a long-term employee of E.I. du Pont de Nemours & Company who created an invaluable photographic record of the company's Brandywine Mills at the turn of the century. Gentieu was born in France in 1842. He emigrated to the United States around 1859. As a member of the local militia in New Orleans, Gentieu refused to swear allegiance to the Confederacy and was shipped north at the beginning of the Civil War. He later enlisted in the 13th Connecticut Volunteers. He began working for DuPont in 1877 and remained a loyal employee until his retirement.