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, number of stories, building use, and more. The maps were originally produced for insurance underwriters, but today are used by researchers in history, urban geography, architectural history, and other fields. They are commonly referred to as Sanborn maps because the Sanborn company was the largest national producer, covering the United States, Mexico, and Canada.
The Earth Sciences & Map Library has a large collection of fire insurance maps for California, consisting mostly of online and microfilm sets. The Bancroft Library holds original fire insurance maps for some cities in California.
Use our microfilm collections to find other fire insurance maps.
To find other fire insurance maps in our collections, use the Advanced Search in UC Library Search to search for the subject keywords [fire insurance place name maps] (e.g., fire insurance nevada maps).
The Center for Research Libraries (CRL) holds microfilm for all Sanborn fire insurance maps in the Library of Congress (1867-1970), and eligible UC Berkeley faculty and students can borrow the microfilm through Interlibrary Borrowing Services. Please contact the librarian for a consultation if you need Sanborn microfilm from CRL. Note that the Digital Sanborn Maps largely duplicates the CRL microfilm collection.
Note: Most libraries only hold fire insurance maps for their own state.
Fire insurance 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.
NOTE: Most updated versions of Sanborn (and other fire insurance) maps are original editions with pasted-on correction slips. In such cases, the date of the information is usually a penciled date contained in a "corrections box" at the beginning of the set or volume, rather than the date appearing on the title sheet.
Listed below are some resources that can help with the interpretation of Sanborn and other fire insurance atlases: