Davenport, Iowa fairgrounds hosts an antique motorcycle swap meet. This happens on Labor Day weekend. Friday night has vintage dirt track racing on the 1/2 track. Board trackers from the early days, to stuff from the 70's & 80's. The swap meet has a lot of American stuff, with English and Japanese in lesser numbers. There is also a bike judging contest of the old bikes. Many cool things to see, and the parking lot has a wide variety of bikes parked there. My friends and I have been going for years and loving it.
Steve_K