University Libraries

Photo courtesy of bluefizzure

Check out a local university library. I live near the Milwaukee, Wisconsin area and searched for our local University-Wisconsin library. They have an entire rare collection that you can see if you go there, including things like Charles Lindberg's flight map when he made his legendary non-stop trip to Paris. So check out some local, non-public libraries. Most will even allow you to check out books if you have a library card at a local public library (but you might need to get a separate one for the university library). I also noticed a large, online virtual collection of antique photos, including ones of the city, aircraft, vehicles, maps, etc.