Sanborn maps are valuable historical tools for urban specialists, geographers, planners, environmentalists, and anyone who wants to learn about the history, growth, and development of American cities, towns, and neighborhoods.
Sanborn maps, produced by the Sanborn Map Company, the primary American publisher of fire insurance maps for nearly 100 years, are valuable to anyone who wants to learn about the history, growth, and development of American cities, towns, and neighborhoods. They are large-scale plans containing information that was used to estimate the potential risk for urban structures. Information includes the outline of each building, the size, shape, and construction materials, heights, and function of structures, location of windows and doors. The maps also give street names, street and sidewalk widths, property boundaries, building use, and house and block numbers.
Textual information on construction details (for example, steel beams or reinforced walls) is often given on the plans, while shading indicates different building materials. Extensive information on building use is given, ranging from symbols for generic terms such as stable, garage, and warehouse to names of owners of factories and details on what was manufactured in them. In the case of large factories or commercial buildings, individual rooms and the uses to which they were put are recorded on the maps. Other features shown include pipelines, railroads, wells, dumps, and heavy machinery.
140 map sets are available for Delaware, ranging in date from 1884 to 1958. A key provided by the Sanborn Map Company provides information on the notation of map features.
The Library of Congress has made thousands of Sanborn Fire Insurance Maps available online for many buildings in U.S. cities and towns. These maps are in color.
Sanborn maps for Delaware are also available on microfilm (Microfilm no. 3333, 3 reels). Later coverage for some Delaware cities is available on an an additional reel (Microfilm no. 5690).
Sanborn maps for several nearby states are also available on microfilm: District of Columbia (Microfilm no. 3338 and no. 4614), Maryland (Microfilm no. 3368 and no. 4741), New Jersey (Microfilm no. 3519 and no. 4612), and Pennsylvania (Microfilm no. 3332 and no. 4613).
NOTE: The original maps are color coded. The maps in this database and on microfilm are black and white.
