Sanborn Fire Insurance Maps
These large-scale maps showing the commercial, industrial, and residential sections of some twelve thousand cities and towns in the United States, Canada, and Mexico were designed to assist fire insurance agents in determining the degree of hazard associated with a particular property. They show the size, shape, and construction of dwellings, commercial buildings, and factories as well as fire walls, locations of windows and doors, sprinkler systems, and types of roofs. The maps also indicate widths and names of streets, property boundaries, building use, and house and block numbers. Locations of water mains are shown, with their dimensions, as well as fire alarm boxes and hydrants.