It's nothing more than a small stone obelisk, but it has huge historic significance. And it's likely the least known monument on Lake Michigan.

It's called the Illinois-Indiana Boundary Monument and it's tucked away on the border line between Chicago and Hammond. The only way to access the monument is via Illinois, using Avenue G through Chicago's Calumet Park. The marker sits near a former power plant just over the state line in Indiana.

The monument marks the line between the two states some 159 miles north of the Wabash River that defines the southern end of the states' border.

The small stone structure is also one of the oldest in Chicago. The city's website notes:

One of the oldest extant structures in the City of Chicago, the Illinois-Indiana State Boundary Marker was constructed to commemorate the establishment of the common boundary between the two states in 1833. Boundary surveying was necessary for the sale of land within new states and territories, and commemorative markers were often erected following the establishment of such boundary lines. Built of large sandstone blocks, the marker is in the shape of an obelisk, a traditional form for commemorative markers. In 1988 the marker was relocated approximately 191 feet north of its original site, but remains on the state line.

Virtually Tour the Monument

The photos below show the plaques that once adorned the 4 sides of the monument.

Sadly, this 2016 video shows the plaques are now gone, apparently the work of vandals.

This video gives you a very nicely done history of the monument.

Visiting the Marker

The marker is a public park and open to anyone. However the road to get there will feel a bit deserted as the neighborhood fades away and the power plant adjacent to the monument is now abandoned. Here are the directions via Google Maps.

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