Research Guides: Sanborn Map : Digital Sanborn Maps

Finding a Map

To access the Digital Sanborn Collection you must be a student, faculty or staff member at the University of Maryland, or be using a computer in one of its libraries.

Digital Sanborn Maps
Fire insurance maps are a core resource for documenting the development of neighborhoods over time. Founded in 1867, the Sanborn Map Company was the primary American publisher of fire insurance maps for nearly 100 years. They show lot numbers, square footage of lots, street addresses, which lots have buildings and their shape and materials. They indicate the type of construction, property lines, and the number of stories. They can narrow the date when a building was constructed. They can be used to track demolition, recent construction and alterations. They identify plot numbers necessary to access deed and other civil records. This digital product provides access to the maps of all United States' states. Users have the ability to easily manipulate the maps, magnify and zoom in on specific sections, and layer maps from different years. 1867-1970

Follow these steps to find your area of interest on the Sanborn Maps. For example, if you are interested in Washington, D.C. in 1939:

From the main page of the collection, select "Browse Maps" under the introductory paragraph. A series of drop-down menus will subsequently appear. The first menu asks users to select a state. Select District of Columbia.
Once you have selected District of Columbia, another drop-down menu will appear. Select a city from the drop-down menu. Click on Washington, D.C.
Clicking on the city reveals a date drop-down menu, which displays the editions produced for that city or town. Select your date; for our example select 1939 from the drop down menu. Selecting a date brings you to a screen depicting up to 25 images of the map sheets. To see more pages, click on the "Next" button at the bottom right of your screen, or, choose a specific map from the drop-down menu at the bottom center of the page.
Consult the edition's index map often called the "key," before searching for a particular urban location.

Index maps display the entire city (or the portion of the city contained within that volume) and label city blocks with numbers that correspond with their sheet number. Since there is no street name index, it is important that you have an idea as to where in a city your street or neighborhood of interest is located before you begin using the Sanborn Maps.
Index maps are always in the beginning of a map collection, so they are among the first sheets listed. They can be identified in the thumbnail collection as the only map that shows the entire city and the only map that also contains an atlas key. In our example, the Washington, D.C. index is sheet 0a.

For more information about displaying and working with the maps, see the Displaying and Working with the Maps page of this guide.

Finding a Map - Visual Steps

Digital Sanborn Map Website

Finding a Sanborn Map by state, city and date

Thumbnails of Washington DC Sanborn Map Sheets. Index or key maps are Sheet 0 and Sheet 0a. Sheet 0a shows Washington, D.C.

Additional Site

Sanborn Fire Insurance Maps at Library of Congress
The Library of Congress has been digitizing Sanborn Fire Insurance Maps in color and has made them available at the Geography and Map Reading Room website. Not all of the maps are available at this time but many of the earlier maps are online.
Sanborn Maps Instructions and Essays
Instructions on how to view and use the Library of Congress' collection of Sanborn Maps. Also includes essays about the maps and information about rights and access to the maps.