William du Pont, Sr. (1855-1928) was an industrialist and member of the prominent du Pont family of Delaware, whose family business was the E.I. du Pont de Nemours & Company, also known as the DuPont Company which was a large manufacturer of gunpowder. He worked for the first DuPont dynamite manufacturer, Repauno Chemical Company, as secretary and treasurer (1880-1884) and after the tragic death of Lammot du Pont (1831-1884), as president (1884-1892). William du Pont, Jr. was the youngest child of du Pont, Sr. and Annie Rogers Zinn du Pont (1858-1827). Du Pont Jr. became the president of Delaware Trust Company in 1929, the youngest bank president in Wilmington at that time. In 1952, he became chairman of the board, retaining both positions until his death in 1965. This collections consists of photographic material mostly relating to the U.S.F. Powder Company, together with the Ball Grain Explosives Company which was in a way U.S.F. Powder Company predecessor. It also includes William du Pont's family photographs and negatives.