Friday, March 27, 2015

Researching Sanborn Insurance Maps | 1 Comments - Click Here :

    Peter F. Brauer  - The valuation records in the custody of the National Archives were created as a result of the Valuation Act of 1913. Railroad companies prepared maps and forwarded them to the Interstate Commerce Commission (ICC). The ICC reviewed, annotated and maintained these maps to help evaluate railroad corporate property which was used as a basis for fixing rates that would yield a reasonable profit to the railroads.

    The Cartographic Section maintains two series of Valuation Railroad Maps. The first covers the years 1915-1920 and the second, revised series covers the years 1920 to 1960. Both series of valuation maps consist of right-of-way, tract and station maps annotated to some degree with color markings to show railroad property changes. The majority of the maps are blueprints measuring 24 by 56 inches. Coverage is nationwide and arranged alphabetically by railroad name, there-under alphabetically by state, when listed, or numerically by valuation section, there-under numerically by map number. Individual map sheets typically contain information on land acquisition, such as grantor and grantee, and engineering information, such as the layout of track, the locations of roads, and railroad buildings and bridges. The scale of the maps range from 1 inch to 100 feet to 1 inch to 400 feet. 

    The revisions include new acquisitions to the railroad or track/property no longer in use between 1920 and 1960. Revised maps were often not created when there were no significant changes to document. Therefore, gaps in coverage do exist at the railroad, valuation section, and map level. Combined, the two series consist of nearly 250,000 maps. 

    We do not have a database listing every valuation map in our custody. We have coverage for nearly every standard gauge freight carrying railroad operating at the time of the valuation survey during the 1910's in the conterminous United States. This excludes interurban passenger railroads, narrow gauge, trolley, and most logging and mining railroads. We have index maps in our research room and filed with the records that show the extent of valuation sections and in some cases the coverage of individual maps. 

    You may search for specific railroads using the National Archives’ Online Public Access (OPA) at These catalog entries are intended to give researchers a general description of records held by the National Archives. The catalog does not provide an item level index of the maps or access to digital versions of the maps. 

    If a researcher is looking for a specific railroad covering a specific area they may provide us, via email to, with as much information as possible (e.g. railroad name during the early twentieth century and coverage area including town, county, state, township and range coordinates, etc.). Once we receive this information, our staff we determine if any maps exist within our holdings, and if so will provide citations for ordering copies. 

    Copies of large-format maps and plans can be mail ordered from authorized vendors. All copy orders are custom orders, and copy costs are determined by the size of the record and the type of copy requested (electrostatic, photographic, scanned, etc). The least expensive copy of an average size map or plan in our custody is over $50.00. Any questions regarding copy formats and costs should be directed directly to the vendor. A list of private vendors may be found at the following web address: 
    Researchers may also visit our research room located at 8601 Adelphi Road in College Park, Maryland. There you may view the records and place an order for any copies you would like to purchase. Our public service hours are Monday through Saturday, 9 a.m. to 5 p.m. We have closed stacks, meaning records are brought out to researchers five times per day at 10:00, 11:00, 1:30, 2:30, and 3:30 Monday through Friday. Records are not pulled on Saturdays. Black and white photocopies can be obtained in our research room for $3.50 a linear foot ($5.00 for color), although there is a ten copy per day limit. Scanned reproductions are $3.50 each with the same copy limit of 10 per day. The use of non-flash photography is also permitted. No appointment is necessary. For additional information regarding research room hours please see our website at

    If you require extensive research you may wish to hire a private researcher to conduct paid research on your behalf. Information regarding this research option can be found at: The textual records of the Interstate Commerce Commission that relate to the railroad valuation maps are also housed at our College Park Facility within the Textual Records Division. These records include information on railroad facilities and property, land acquisition and appraisal, engineering field notes, railroad inspection reports, annual reports of railroad companies, railroad abandonment, and railroad accident reports. An article summarizing the textual railroad records in the National Archives can be found at
        Reference inquires relating to these records may be emailed to
Peter F. Brauer 
Archivist - Cartographic Section National Archives and Records Administration 
(P) 301-837-2036 
(F) 301-837-3622 
1 Comments - Click Here :
  1. Interesting and useful! I just checked and there is a listing for the DB&W RR in the archives. Now if I was if I was only still traveling to Maryland for work!