Wilmington, DE
The Hagley Museum in Wilmington, Delaware, occupies a former 19th‑century gunpowder plant that remains in use for demonstrations. Visitors can walk through the historic buildings and surrounding grounds, either following a self‑guided route or joining scheduled demonstrations. The museum also hosts the Nation of Inventors exhibit, which highlights diverse contributions to American innovation. The site is open daily from 10 a.m. to 5 p.m., with the last admission at 4 p.m.