Sanborn Fire Insurance Maps


What are they?

"Fire insurance maps are detailed city plans, usually at scales of 50 or 100 feet to an inch. They show individual building "footprints," complete with construction details, such as building material (brick, adobe, frame, etc.), height (of larger buildings), number of stories, location of doors, windows, chimneys and elevators, use of structure (dwelling, hotel, church, etc.), street address, and occasionally the ethnicity of the occupants. Other features shown include lot lines, street widths, water pipes, hydrants and cisterns, and fire-fighting facilities.

The maps were originally produced for insurance underwriters, who used them to determine risks and establish premiums. Today these maps are used by scholars and researchers in such fields as history, urban geography, architectural history and preservation, ethnic studies, and urban archaeology.

One of the earliest fire insurance maps is Richard Horwood's 1792-1799 map of London. Plans for American cities became widely available in the mid-nineteenth century. The earliest extant one for a city in the western United States is S.J. Gower's 1851 "Map of the Burnt District of San Francisco Showing the Extent of the Fire." Relatively few insurance maps made before 1884, when copyright deposit in the Library of Congress was required, survive. Sanborn maps are produced today, primarily for major cities and by contract for smaller ones."

There is a lot of work being done these days on researching the growth of cities and villages, but there are very few places on the internet people can go and find the information that is easily found on these maps. It is very interesting and beneficial to look up a street corner in your home town and see what was there in 1895. It's the intention of the Clinton County GIS department to make this information available with a minimum of effort for all the areas in Clinton County that are covered by these maps.


Link to Library of Congress:


Ohio Public Library Information Network:

Ohio Web Library

Implementing Digital Sanborn Maps for Ohio:  (Article)


Digitizing Sanborn Fire Insurance Maps for Full Color, Publicly Accessible Collection:  (Article)