Fire Insurance Map

Tombstone, Arizona
(New York: Sanborn Map and
Publishing Company, 1886)
Geography & Map Division

Insurance Maps of
Pittsburg [sic], Pennsylvania. Vol. 2.
New York: Sanborn-Perris
Map Company, 1893
Color lithograph printed map
Geography & Map Division
Copyright deposit 1893 (117.7)

Reno, Nevada. Sheet #5
New York: Sanborn Map and
Publishing Company, 1899
Color printed map
Geography & Map Division
Copyright deposit (117.10)

Insurance Maps of Williamsburg,
James City County, Virginia.
New York: Sanborn Map
Company, 1910
Color printed map
Geography & Map Division
Copyright deposit, 1910 (117.11)

Insurance Maps of Albia, Iowa
New York: Sanborn Map
Company, 1910
Color printed map
Geography & Map Division
Copyright deposit, 1910 (117.9)

Insurance Map of Los Angeles, California
New York: Sanborn Map Company, 1919
Geography & Map Division

The O.K. Corral, where the notorious gunfight between the Earp brothers and Doc Holliday versus the Clanton gang took place October 26, 1881, is shown (between 3rd and 4th Streets, bounded by Fremont on the north and Allen on the south) in this 1886 fire insurance map of Tombstone, Arizona.

This map is one of over 700,000 fire insurance map sheets produced by the Sanborn Map Company for more than twelve thousand American cities and towns from the 1870s until the 1950s. These maps were prepared primarily to assist insurance underwriters in determining the risk involved in insuring individual properties.

During the first half of the nineteenth century, most fire insurance companies were small and based in a single city. Consequently, the underwriters could themselves examine properties they were about to insure. However, as insurance companies became larger and expanded their coverage to numerous cities, a mapping industry developed to support this need. The Sanborn Map Company of New York eventually came to dominate the insurance mapping business.

As the Tombstone map illustrates, fire insurance maps provide a block-by-block inventory of the buildings in the built-up or congested parts of towns. The outline or footprint of each building is indicated, and the buildings are color coded to show the construction material (pink for brick; yellow for wood; brown for adobe). Numbers inside the lower right corner of each building indicate how many stories the building had, while the numbers outside the building on the street front refer to the street addresses, allowing researchers to correlate these locations with census records and city directories. Individual dwellings are marked with "D" or "Dwg," but the residents or owners are not identified. Factories, businesses (such as hotels, saloons, liveries), churches, schools, and other public buildings (city hall, assay office, library) are labeled by name.

Today, fire insurance maps are used for a wide variety of research purposes including genealogy, urban history and geography, historical preservation, and environmental studies. The Library accumulated its unsurpassed collection of fire insurance maps primarily through copyright deposit. In addition, the Bureau of the Census transferred a set of maps updated with pasted-on corrections through to the mid-1950s to the Library of Congress in 1967.

Another typical example is the 1919 map of a portion of the Hollywood-Colegrove district of Los Angeles showing the Douglas Fairbank Pictures Corporation Studio. While most of the building in the complex, which are devoted to stages, dressing rooms, wardrobe, scene printing, property storage, and projection, are constructed of wood ( indicated by the color yellow), the archives building is the most substantially constructed building, being made of reinforced concrete (indicated by the brown color).

Fire insurance maps, prepared for underwriters, provide block-by-block inventories of individual buildings for more than 12,000 cities and towns from the 1870s to the 1950s. A typical example is this 1893 coverage of Pittsburgh, which was the capital of the world's steel production. Native coke and coal, resources found in abundance in western Pennsylvania, were essential to the production of steel. This map shows the precise layout of the Carnegie and Black Diamond Steel mills on the south side of the city, as well as the close proximity of workers' homes as indicated by the letter "D" for dwelling.

The Sanborn Fire Insurance map for Reno, Nevada, dated April 1899, shows the commercial center of the city, including the railroad tracks and train station, several hotels, and a variety of businesses, most of which were constructed of brick, which is indicated by their pink coloring. The lower right corner shows the evolving ethnic neighborhood of "China Town," located near the Truckee River. The buildings labeled "Female Boarding" were legal houses of prostitution.

Another example is this sheet from the 1910 coverage for Williamsburg, Virginia. It focuses on Bruton Parish Church, the city hall, and the powder magazine, all along Duke of Gloucester Street, constituting the core of the historic restoration initiated by the Colonial Williamsburg Foundation, which is celebrating its seventieth anniversary this year. These maps document the former colonial Virginia capital at the beginning of the twentieth century, just before this major restoration began.