The Henry Ford museum and factory tour in Dearborn, Michigan. The museum is so much more than cars, encompassing innovations in transportation, technology, and history. If you ever have the opportunity to visit, I highly recommend it.
In addition to the onsite displays, they also curate a large digital collection. This could be a great resource for students to interact with primary source documents and media. Experts have collected resources into specific sets such as: The Indy 500, Lincoln's Chair, and American Democracy and Civil Rights.
I would also suggest browsing through their large collection of Educational Resources. The unit plans can be sorted by subject, grade, and time period.