I was reading the blog Style Court and remembered that the New York Public Library is an unrivaled resource not only for research and reference, but for buying your own historic prints. They have a massive digital gallery selection ranging from old maps to science illustrations to Manhattan photography, Japanese woodblock prints to 19th century fashion illustrations, basically, there is something that exists on their database to suit any interest. You can purchase prints of anything you find, and even crop it if you only want one section of a map, etc. Plus, they're only $30 unframed! I think I might buy the above Alexander Anderson print, learn how to decoupage, and then make my own John Derian knock-offs. Check out the NYPL archives for yourself right here.