Sanborn Maps are a valuable historical resource for understanding urban development over a long period of time. The Sanborn Map Company was a publisher of detailed maps of U.S. cities and towns in the 19th and 20th centuries. The maps were originally created to allow fire insurance companies to assess their liability in cities of the United States and so give details about things such as building uses and construction methods.
Please see this libguide for more details about Sanborn map resources available at MSU.