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 all concrete.

If you were only looking at the parcel fabric and not an aerial below it, you could be forgiven for thinking that it’s still a neighborhood. Rather, it is all that is left of the neighborhoods that were destroyed to create the Eisenhower, and these parcels exist for all of the Chicago area expressways.

Cookviewer Image of Active Parcels as of 2024, even though none of these parcels have had any separate land uses since the Ike.

Cook County’s parcel fabric is a digital layer that represents the county’s property boundaries, as an enormous and constantly updated spatial dataset that records who owns what, and where.

But the map is also a kind of memory. Many of these parcel outlines date back nearly a century, their geometry copied forward through generations of surveys, tax rolls, and assessor updates. When the landscape changes drastically, as it did in mid-century Chicago, the parcels often persist as “ghosts,” still recognized in the data even if the ground beneath them has long since disappeared. There is no legal need to combine parcels, and as such, even when the land use represents multiple parcels, they are not often combined, leaving legal scarchitecture, not unlike one of the first topics of this blog. The parcel fabric, in this way, becomes a form of urban archaeology. It preserves the ghosts of streets cut by highways, the footprints of railyards filled in for parking lots, and the edges of industrial corridors that were once the arteries of the city.

Each of these tiny parcels tells a bureaucratic story. Many were acquired by IDOT or the City of Chicago through condemnation, but not always consolidated. Some were reassigned to the CTA for the Blue Line’s median right-of-way. And so these parcels lingered in limbo, technically existing, but without any physical form or taxable value.

The Eisenhower (originally the Congress Expressway) tore through Chicago’s West Side in the 1950s, part of a national wave of urban freeway construction that favored automotive efficiency over neighborhood continuity. 

WBEZ did a fantastic report on the demolition of the neighborhoods that were razed to create the Congress Street Expy called Displaced, which chronicles the 13,000 people who were displaced to create the land for the road.

Demolition on the Near West Side in preparation for the Congress Street Expy (later named Eisenhower) 1949 (University of Chicago Photographic Archive)

Entire blocks of homes and businesses were cleared to make way for up to ten lanes of highway and a new rapid transit corridor to replace the Metropolitan West Side Elevated with a center median line, now known as CTA's Blue Line. (Map of Abandoned CTA Stations)

Englewood 1939 USGS Topo Map with the boundaries 

And of course, these parcels still show how other expressways divided neighborhoods, for example, the Dan Ryan Expy.

Legal parcels of what once were homes, shops, businesses, churches, etc. still exist, despite being nothing but concrete these days.

During the early planning of what would become the Dan Ryan Expressway, the route was originally drawn to cut through Bridgeport; then the home political base of Mayor Richard J. Daley, along Normal Avenue. However, in 1956 Daley and the city council intervened, shifting the freeway alignment roughly eight blocks east to Wentworth Avenue, skirting Bridgeport and instead slicing through mostly Black and working‐class neighborhoods along Armour Square, Fuller Park, Bronzeville, and Englewood. 

"Properties claimed for Construction of Dan Ryan Expy - 1953-1954" - Encyclopedia Chicago

That decision amplified racial and spatial division: the expressway became a literal barrier between white and Black communities, reinforcing segregation patterns, displacing tens of thousands of residents (many Black), and undermining local business corridors and social networks, creating a mappable division on Chicago's South Side. (South Side Weekly)

Author David Obst, in Saving Ourselves from Big Car (2025), argues that the dominance of the automobile, and the vast networks of highways built to serve it, is not merely a technical or transportation issue, but a structural and political one. The “Big Car” complex, as Obst calls it, encompasses the interlocking interests of auto manufacturers, oil companies, insurance firms, concrete and asphalt contractors, and media, all of which shaped policy toward enabling car dependence at the expense of equitable urban form. the case of the Dan Ryan, this dynamic is starkly visible: the freeway was not placed in a neutral vacuum, but dropped deliberately through lower-income and predominately Black neighborhoods, intensifying racial and spatial segregation, destroying local institutions, and entrenching auto-centric mobility over alternative networks. 

The Dan Ryan’s route, rezoning, and clearance policies reflect exactly the kind of decision making Obst warns against where infrastructure is wielded as a tool of consolidation and exclusion, rather than as a public good.

The phenomenon of ghost parcels is not just related to highways and abandoned railroad corridors, however - although they are the most well-known creators of ghost parcels, but the Forest Preserve District of Cook County also has some interesting parcel fabric stories, such as the also-aforementioned Wolf Road Prairie, which is still subdivided despite being (thankfully) preserved. 

CookViewer Map

Evidently, IDOT also acquired land at some point to improve the interchange at LaGrange Rd and 95th St. 

That land parcel looks perfect for an intersection improvement, although as of now I think it's fine the way it is.

The persistence of these parcels tells us something profound about how cities evolve. Streets, buildings, and entire neighborhoods can be erased in what feels like no time at all, but property lines can linger for generations, encoded in public records, legal descriptions, and assessor maps.

Thanks as always for reading!