Sanborn maps date back to the 1860s and were created as a detailed building record by the Sanborn Fire Insurance Company.  They are large scale (50 feet to the inch) and highly detail and include such information as building location, construction materials, and building height.

Digital Sanborn Maps is an online resource consisting of scanned black and white images of Sanborn maps for Missouri.

Washington University Libraries and the Missouri History Museum hold approximately 3,300 fire insurance maps produced in St. Louis by Alphonso Whipple between 1870 and 1898. Currently, use of these maps is restricted by their brittle condition, but through this joint digital project, are now being made available to the public.