Beneath the Pavement: Hidden History in Cook County’s Parcel Fabric

If you zoom far enough into Cook County’s parcel data , you’ll find something strange. Beneath the steady roar of the Eisenhower Expressway (I-290) under the lanes of traffic, the CTA Blue Line tracks, and the median embankments, lies a full grid of property parcels. Every one has a unique PIN, neat cyan lines drawn as though the houses, alleys, and corner lots were still there. To the eye, it’s…