The National Museum of Industrial History, the Smithsonian Museums’ first affiliate, tells the story of America as an industrial powerhouse of steel, silk, and propane from the 19th to 20th centuries. Housed in a 13,000-square-foot, 100-year-old, former Bethlehem Steel facility, the museum focuses on the industrialism of Pennsylvania’s Lehigh Valley, and expands its scope to explain the international impact of the industry.