Digital Sanborn Map Collection

Scope:This guide is intended to aid in the navigation of the Digital Sanborn Collection. In addition to the Digital Sanborn Collection, the University of Maryland Libraries holds a collection of colored print maps for a number of communities in the state of Maryland and the District of Columbia. If you are interested in the Sanborn Maps available in print, click here.

Email the subject area specialist or call 301-405-6320 for more information.

Table of Contents

• Overview
• Finding a Map
• Displaying and Working with the Maps
• Some Notes about the Digital Sanborn Maps
• Capturing an Image from the Sanborn Maps
• Additional Information and Links

A. Overview

The Sanborn Map Company played a vital role in the development of fire insurance map making in the late nineteenth and early twentieth centuries. Founded by D.A. Sanborn in 1867, the company created hand-made and colored lithograph maps of over 12,000 cities and towns across the United States and set the standard for fire insurance maps of the era. Today, Sanborn Maps provide us with a detailed understanding of the physical make up of these cities and towns, and give us insight into the existing social, political, and economic conditions in specific places and times.

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B. 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. Start at the University of Maryland Libraries Website . From there, select the "Research Port" option. Click on the "Database" option and search "by Database Name". Above the search space, click on the letter "D". This will lead you to a list of databases starting with the letter D, including the Digital Sanborn Maps. Select the "Digital Sanborn Maps" and you will be taken to the homepage. 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.

1. 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.
2. 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.
3. 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.
4. 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.

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C. Displaying and Working with the Maps

Continuing with our Washington, D.C. example, if you're most interested in area around Brookes Avenue in the Capitol Heights neighborhood in the south east of D.C. use the following steps to get a closer look of the specific neighborhood or street.

1. To find the appropriate map sheet, click on the index map (sheet 0a). Because Washington, D.C. is a larger city, there are several volumes of this map; however, only the second volume from 1939 is available to us. Select the index key in volume two.
2. To enlarge the display window, select a larger blue box from the "select window size" option. This will make the display area larger, but you may have to increase your browser window accordingly. You can also zoom in on the image using the drop-down menu or the zoom button at the top of the window.
3. There are two ways to navigate around the display window: by clicking on the arrows on the four sides of the box, or by clicking on the re-center button at the top of the box. When re-center is selected, clicking on a point in the window will redraw the image with the selected point at the center.
4. Use all of the previously mentioned tools to get a closer look at the area around Brookes Avenue in Capitol Heights. The large numbers on the map tell you on which sheet you can find a more detailed, close-up map of this area.
5. Select a map using the thumbnail or scrolling menu. For our purposes, use sheet 450 to get a closer look at Brookes Avenue in Capitol Heights. Minimize the index map and take a look at the thumbnail page. If sheet 450 is not displayed, select it by clicking on it in the drop-down menu at the bottom of the thumbnail page. A new viewing window will open with just sheet 450 in it. The window with sheet 0a in it, the index map, will not close or be reloaded, allowing us to look at several sheets at once. With sheet 450, you can now find more detailed information about the neighborhood around Brookes Avenue, as well as the specific building numbers.

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D. Some Notes about the Digital Sanborn Maps

1. Some dates are listed twice under the "select a date" drop-down menu, indicating one atlas held by the Census Bureau and one by the Library of Congress. Census Bureau maps are indicated by an asterisk (*). Corrections between editions were pasted onto these maps and not on maps held by the Library of Congress, so they are not identical. A map edition that shows a brief range of years means that the maps took that period of time to produce. Maps with longer ranges indicate pasted-on corrections were made to that map over that period of time from when it was first produced.
2. For large cities, maps are divided into multiple volumes for a particular publication year. If a year's edition had to be broken up into volumes, a new drop-down menu will appear at the top of the thumbnail page. Volumes are organized geographically, so consult the index map at the beginning of each volume to note what portions of a city are represented by what volume. On each index map you will find another map, called an insert map, in one corner with the city divided into several sections. The numbers in each section designate in which volume you can find your desired area.
3. At any time, you can change the city, date, or volume number of the Sanborn Maps displayed by clicking on the drop-down menus at the top of the thumbnail page.
4. Help with the page and collection is also available at the header present on all pages of the web collection.
5. Editors Notes, taken from the Library of Congress' published index of Sanborn Maps in its collection, appear in a pop-up window if you click on the "Editor Notes" link at the top of the page. Usually these notes indicate when nearby towns or suburbs have been included in a Sanborn edition.
6. Every time a thumbnail is clicked, a new window opens, displaying that map sheet instead of reloading a single window.
7. The Sanborn Maps are available both online and in microfilm in black and white, and the original maps in the Library are in color. The color maps give greater detail about the structures, while the black and white versions are less descriptive. To decipher the maps, utilize the following resources.

• A black and white key for use with these maps is accessible directly by clicking here.
• A color key for use with the original maps is accessible directly by clicking here.

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E. Capturing an Image from the Sanborn Maps

1. You can download the map as a .PDF file by clicking "Download Map" from the title bar menu. The PDF formatted file will open in a new browser window. To save it, click on the disk in the toolbar, or click File>Save As from the file menu of the web browser.
   • PDF's can be opened in Photoshop versions 5 and higher and further manipulated or printed. To open a downloaded Sanborn image in Photoshop, click in File>Open As and specify "Generic PDF" as the type of file.
2. You can also print the map from the view window by clicking "Print Current Window" from the title bar menu. This function captures the image as shown in the view window and transfers it to a new browser window, from which it can be printed. Only the portion of the image shown will be printed, so this function is suitable either for printing small images of the full map sheet or a zoomed-in image of just a portion of a map sheet.
3. It may be necessary to re-center the image using the re-center tool in the window before printing. Selecting the size of the window by clicking on the blue boxes above the window will also affect the area captured for printing, so it may take some experimentation to capture exactly the area you want to print.

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Additional Information and Links

Sanborn Maps of Maryland/Washington DC. This site provides a list of Sanborn Maps available in print in the Maryland Room at the University of Maryland, College Park.

The History of the Sanborn Map Company. This site provides a brief history of the Sanborn Map Company in the United States.

Digital Sanborn Maps. http://sanborn.umi.com. This links to the Digital Sanborn Homepage.

Sanborn Map Company. http://www.sanborn.com. This links to the hompage of the modern Sanborn Map Company.

Another State Repository with access to the Digital Sanborn Map Collection is the Enoch Pratt Free Library in Baltimore City. Online access to the maps is available anywhere for library card holders.

**This page was adapted from The Geospatial and Statistical Data Center, University of Virginia Library. "Sanborn Insurance Maps User's Guide," http://fisher.lib.virginia.edu/collections/maps/sanborn/web/umiguide.html, 09/06/05.

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