This reminds me that Art Thieme has a most wonderful geographical reference map of American folksongs. I wish it were readily accessible online.

Where was this site, when I was in high school? (Nevermind, I guess we were still messing around with UNIVAC in those days!) I managed to fake my way through history and literature classes by creating presentations of things like "Songs of American Wars" or whatever. A reference like this one would most certainly have been of much help.