Henry Miller (1845-1926) was first employed at the Brandywine Works of E.I. du Pont de Nemours & Company. In 1922, he was one of the oldest surviving employees when he was interviewed by Alfred I. du Pont (1864-1935). In the interview, Miller describes the layout of the Brandywine Works as it changed over time, as well as the various apparatus and processes used in the manufacture of gunpowder and its constituent ingredients.