The "Eve N Don" site has a cornucopia of delightful items for the genealogist. There's a link to directories, small books, yearbooks, census and military.
Being that we're camped near Decatur, Illinois, as I write this, the 1874 Decatur, Illinois, Directory, which included a brief history of the area, piqued my curiosity. The section written by Professor Gastman, whose career was featured at the Macon County, Illinois, Historical Museum, illustrated a school curriculum for 1874.
There's material from several different states as well as a few international links. A very nice (and growing) collection.