Sanborn Maps were produced by the Sanborn Map Company during the 19th and 20th centuries for use by fire insurance companies in urban areas of the United States and some other countries. These details maps plotted out each structure on each street, waterways, railroads, parks, etc. These provide an excellent look back in time at a city or other urban area, and can be overlaid on top of present day maps using tools like Google Earth.
The Library of Congress provides free access to Sanborn Maps that <strong>reside in the public domain</strong>. Many of these have been digitized and are available online.