It looks like you're using Internet Explorer 11 or older. This website works best with modern browsers such as the latest versions of Chrome, Firefox, Safari, and Edge. If you continue with this browser, you may see unexpected results.
"Sanborn maps are large-scale plans of a city or town, drawn at a scale of 50 feet to an inch. They were created to assist fire insurance companies as they assessed the risk associated with insuring a particular property. The maps list street blocks and building numbers including numbers in use at the time the map was made and previous numbers."