These maps, created by the Sanborn Map Co. to evaluate potential fire hazards in communities, provide insurance agents with the size, placement, square footage and building materials of our ancestors’ properties. First drawn in 1867, Sanborn maps are notable for their detail and use of symbols, often with color-coding to indicate building material (stone, adobe, brick, etc.).
That level of detail provides interesting information about our ancestors’ homes and workplaces. Sanborn maps’ consistency allows you to watch your ancestors’ living and working environments transform across generations and see their communities change over time.
The Library of Congress has an extensive collection of digitized Sanborn maps at <loc.gov/collections/sanborn-
maps>. Local public and university libraries may offer digitized or printed maps for the surrounding region. Your library may subscribe to a Sanborn map database available through ProQuest.
This map from the Library of Congress’ collection depicts West Chester, Pa., in 1886. According to the collection’s key (on the first sheet of this county’s maps), yellow buildings are “frame,” while red signifies brick; and blue, stone. One building may actually be made up of different materials.