Historic Sanborn Fire Insurance Maps and Baist Real Estate Atlases are an easy way to learn the lot and square number of your home. These numbers will be helpful later in your research. Alongside the lot and square numbers, the Sanborn Maps date from the late nineteenth century and can reveal the change in a parcel of land through its history.
You can trace the date of your home's construction, the building materials, methods of heating, additions, and other changes to the house, as well as changes in street names. The maps also provide context for your home. You can find local schools, churches, shops, and other sites relevant to your home through the past.
Sanborn Maps are available in the Maryland Room at the University of Maryland Library, in both paper and digital form. For more information about the Sanborn Maps, consult the Guide to Using the Digital Sanborn Collection.
Library of Congress’ American Memory Map Collection has a variety of historic maps of the Maryland and District of Columbia areas. Although most of these maps are not as detailed as the Sanborn Fire Insurance Map Collection, they can reveal useful information about the geographic location of your property during a certain time period. For example, you can find out if the surrounding area was urban or rural, names of nearby property owners, and its proximity to railroads.
Other useful maps include planning and city or county maps and Plat books available at a city hall, county courthouse, or local library, as well as atlases which show geographical features and can be found in libraries and archives. See the list of links to the left for more information on map collections that are available.