Sanborn fire insurance maps are the most frequently consulted maps in both public and academic libraries. Sanborn maps are valuable historical tools for urban specialists, social historians, architects, geographers, genealogists, local historians, planners, environmentalists and anyone who wants to learn about the history, growth, and development of American cities, towns, and neighborhoods. They are large-scale plans containing data that can be used to estimate the potential risk for urban structures. This includes information such as 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.