# Historical maps locators Each Property Report for a Chicago-based address or PIN has a Historical maps locator feature which links the reader to 80 Acres maps, Sanborn fire insurance maps, and Cook County tax maps (sometimes called Sidwell maps). None of these maps are hosted on Chicago Cityscape but the locator will identify the correct page of the map databases and open the map file on the databases' respective hosts.  ## Accessing the historical maps locators 1. In a Chicago-based Property Report, select "Historical maps locators" in the table of contents. The page will automatically scroll down to the Historical maps locators section. 2. Select the image for the map you want to see. 3. After selecting the image, a map will appear showing green boxes around the Property Report's location (indicated by a blue house icon). Select the green box that contains the location and then select the link inside the popup that appears. 4. A new web browser tab will open on the map database's host server and will show the map that represented by the shape of the green box you selected. ## About the maps ### 80 Acres maps Each 80 Acres map shows 80 acres of Chicago and contains survey information including [house numbers](https://www.map-strategies.com/blog/2018/10/24/getting-the-building-address-you-want-in-chicago) and lot dimensions. They also show subdivisions. Also view the City of Chicago's 80 Acres [citywide interactive map](https://gisapps.cityofchicago.org/mapchicago/?config=acre). These are hosted by the City of Chicago. ### Sanborn maps Each Sanborn map shows Chicago buildings as they were in the late 1980s and/or early 1990s. These are hosted by the City of Chicago. *See also: [[Property history]]* which highlights alternative ways to find Sanborn fire insurance maps, including from different periods, as well as historic aerial photos. ### Tax maps Cook County tax maps (sometimes called Sidwell maps) show the boundaries and PIN for each parcel. They also show subdivision names. These are hosted by the City of Chicago for the 2021 tax year. # Related articles - [[Property history]] (includes information on how to access older versions of the Sanborn maps and find historic aerial photos) - [[Demographic data]] - [Finding historical Census data to determine unit count](https://www.stevencanplan.com/2023/03/determining-dwelling-unit-count-at-an-address-using-1950-census-records/)