SANBORN FIRE MAPS

Sanborn Fire Maps. Fire insurance maps provide historians with a wealth of information. While they do not show the names of property owners as some rural plat maps provide, a researcher can find a house or other building on the map and learn something about the structure including its relative position to other houses on the same street or block.

One of the largest creators of fire insurance maps was the Sanborn Company. The firm, founded by D. A. Sanborn in 1867, created fire insurance maps from 1867 until 1961 and periodically updated maps for 12,000 American cities and towns. The majority of the maps are from the years of 1876 to 1961; some areas have as many as seven or eight editions. Insurance underwriters used the maps to determine risks and establish premiums. The maps are now used to view urban growth and development. Maps can show:

  Building material
  Height or number of stories
  Doors, windows, chimneys, elevators
  Address and lot lines
  Use (dwelling, hotel, church, etc.)
  Street widths, water pipes, hydrants, and cisterns

The maps include text or abbreviations to describe the purpose of the building, whether a dwelling, a factory, or a business. The maps are frequently drawn with a scale of 50 or 100 feet to one inch.

Sanborn maps showing the Wm. Ryan Packing Company. Photo courtesy: Bob Reding