This museum, in the atrium of the US Patent and Trademark Office, tells the history of the United States patent. Step inside to see where the story started in 1917 in Memphis, Tennessee, when a wholesale grocer named Clarence Saunders invented and patented what he called ‘self-servicing’ stores, now commonly known as supermarkets.

Incidentally, he went from rags to riches and almost back to rags again, but you’ll have to visit the museum to get the rest of the story, along with displays depicting other famous and influential patents. It is about a third of a mile from the King St Metro station; take Diagonal Rd south to Dulany St.