Sanborn Fire Insurance Maps

Sanborn maps are a great source of the architectural history of a city. Not only can you learn when a structure first appeared in a range of years, you can also see if the structure changed is size or construction materials. If you are not already familiar with interpreting the maps, you should go to this site to learn about them: https://www.loc.gov/collections/sanborn-maps/about-this-collection/

Once you are familiar with the color coding and other features of the maps, you can search the maps themselves: https://www.loc.gov/collections/sanborn-maps/?fa=location:arizona%7Clocation:tucson