Steamboat Gardens has been a fixture in Waterloo, Iowa since 1933. The original building actually was built to resemble a steam tugboat. Waterloo has been an industrial and railroad town for as long as the Gardens has been serving burgers, and the restaurant is a gathering place for workers from John Deere and other local factories.
The hamburgers were excellent the last time I ate one there, but that was in 1977, when I picked up this nifty peek-a-boo pinup calendar. I see from their online menu that you can still get the frog legs.
The building may have changed, but one thing sure hasn't. It wouldn't be a good idea to wear your "Stamp Out CommUNIONism" shirt to Steamboat Gardens. Waterloo is a union town.