Old Maps Online, a collaboration of The Great Britain Historical GIS Project based at the University of Portsmouth, UK and Klokan Technologies GmbH, Switzerland, is a portal to digitized historical map collections. The site provides links to maps of various parts of the globe, including historical maps of Ohio. For instance, see an 1804 Ohio map and an 1872 Ohio railroad map from the David Rumsey Map Collection.
Legal information and research resources from The Ohio State University's Michael E. Moritz Law Library