1. Parenting
You can opt-out at any time. Please refer to our privacy policy for contact information.

Discuss in my forum

Kimberly Powell

Exploring Sanborn & Other Fire Insurance Maps Online

By March 31, 2014

Follow me on:

Noblestown, PA, Train Depot, c. 1908Fire insurance maps, produced by SanbornŽ and a number of other companies, are large-scale historical city/town maps that document the size and shape of buildings, locations of windows and doors, and construction materials, as well as street names, and property boundaries. Dating back to the mid-1800's, fire insurance maps were originally created to assist fire insurance agents in assessing potential fire risk, and setting insurance premiums, therefore they also include details such as the direction of prevailing winds, fire department locations and equipment, and the location of fire hydrants and other water supplies.

While big cities were a large target for fire insurance plans, small towns were mapped more frequently than you might expect. In many cases, fire insurance maps document structures and even towns that no longer exist. The small village of Noblestown, Pennsylvania, falls into this category.Downham Real Photo Post Card RPPC, c. 1908 The location where this small community once bustled around booming oil wells and coal mines is now occupied by forest, a few homes and churches, and the trail head on Mill Street where I often begin bike rides on my local rail trail--a crushed limestone trail that follows the path of the former Panhandle Division--Pittsburgh, Cincinnati, Chicago (P.C.C.) & St Louis--of the Pennsylvania Railroad.  If not for old maps, histories, and photographs like the one depicted here, I would never know that a railroad station, two hotels, several general and feed stores, and multiple railroad tracks existed in the spot less than a century ago.

The tiny village of Noblestown was founded about 1796, making it the fourth oldest community in Allegheny County after Pittsburgh, Elizabeth, and McKeesport.1 By 1843, the small community had grown to a population of 250 residents, with one church, a steam grist-mill, a saw mill, and three stores.2 Oil drilling and coal mining during the latter part of the 19th century caused the population to swell with people eager for work, a time when many of the buildings pictured here were built. The town thrived for several decades, but as coal mines began to close in the 1930s, the town declined and is now back to a population of about 575.3

Noblestown - 1915 Sanborn Map - Closeup ViewA 1915 Sanborn fire insurance map for the nearby borough of Oakdale, Pennsylvania, includes a partial sheet on the village of Noblestown. This map is just one of many available online as part of the new collection of Pennsylvania Sanborn Fire Insurance Maps in the digitized collections of University Libraries, Pennsylvania State University. As with most mining communities, the majority of the structures were of wood frame construction--signified by the color yellow. The pink building in the upper left is a brick Catholic church which still stands today, as do the other brick houses pictured nearby, but many of the other buildings no longer exist, including the railroad depot, the hotel, and the stores.

There is a lot of information packed into these fire insurance maps; for example, the two buildings pictured with an "X" are concrete block stables.  Look for the map key to provide information on the symbols, color-coding, etc. Map keys for small towns like Noblestown are fairly simple, while keys for city maps can cover an entire page. The symbols and color-coding remain standard across most map series, with new symbols added as technology advanced. Most towns and cities are covered by multiple map sheets, and the key is often, but not always, found at the beginning of the book, or first sheet of the series for a particular locality. A variety of online guides explain how to use the Sanborn map keys, such as How to Read Sanborn Fire Insurance Maps, originally from the Geospatial and Statistical Data Center (GEOSTAT) of the University of Virginia. The Sanborn Map Company also published a number of booklets called Description and Utilization of the Sanborn Map to help people better utilize their maps, such as this 1949 version, free online at Hathi Trust.

The largest collection of fire insurance maps for the United States was created by the SanbornŽ Map Company of Pelham, New York. The U.S. Library of Congress has the most comprehensive collection, encompassing nearly 700,000 map sheets, ranging from 1867 to the 1960s. The Library of Congress and a large number of state libraries and other repositories have been digitizing many of the pre-1923, out-of-copyright Sanborn map sheets and making them available online. See Sanborn Fire Insurance Maps Online for descriptions and links. It is important to be aware, however, that Sanborn maps do exist from 1923 into the 1960s for many locations. These maps are still protected by copyright, however, and are not included in the online digitized collections.

Sanborn was also not the only game in town! A variety of other companies--many of them working only in specific localities--created fire insurance maps, and you can find some of them online as well. Search "fire insurance" maps locality name and/or browse locality-specific research guides to locate available collections. Examples include the Charles E. Goad Fire Insurance Plan Maps of Canada online at Library & Archives Canada; Hexamer General Surveys of industrial and commercial buildings in Philadelphia from the Philadelphia Free Library; Dakin Fire Insurance Maps from the University of Hawaii at Manoa; and Higginson's insurance maps of the city of Brooklyn from the New York Public Library. The British Library has scanned all first editions of library-owned Goad mapping of British and Irish towns and will be posting them online shortly.


1. Robert G. Larimer, A 200th Anniversary of Noblestown, Pennsylvania, 1796-1996 (Noblestown: R. G. Larimer, 1996).

2. Sherman Day, Historical Collections of the State of Pennsylvania; Containing a Copious Selection of the Most Interesting Facts, Traditions, Biographical Sketches, Anecdotes, etc. Relating to its History and Antiquities, Both General and Local (Philadelphia: George W. Gorton, 1843), p. 92.

3. U.S. Census Bureau, Census 2010, "Community Facts," database, American FactFinder (http://factfinder2.census.gov : accessed 27 August 2013), user-defined report for "Noblestown CDP PA."

April 17, 2014 at 7:37 am
(1) Lee Lewis says:

As an underwriter for the Insurance Co. of North America (INA–no longer in the property-casualty insurance business) in 1959, I used Sanborn Maps to determine the location of buildings we insured and the proximity of other insured buildings nearby to determine our total loss exposure. The proximity of buildings, their construction, and features such as fire divisions–walls with parapets and protective fire doors–and automatic sprinkler systems were all shown on the maps. Obviously we wanted to limit our liability in a catastrophe. When there was too much concentration potential, we would purchase a large deductible reinsurance policy from another company (often $1 million ded. or larger). The purchase was common among insurance companies back then, and still is today.

Without these maps, our ability to predict our loss exposure would not have been possible (no computers back then–everything was on paper).

Leave a Comment

Line and paragraph breaks are automatic. Some HTML allowed: <a href="" title="">, <b>, <i>, <strike>

©2014 About.com. All rights reserved.