A Google Maps mystery. What does the location "1980 Stat Boundary" in Chicago and other larger U.S. cities mean?

While searching Chicago Google Maps, I found an L-shaped street labelled "1980 Stat Boundary" running north from the 2800 block of West Fulton Street and then turning west until it meets Francisco Avenue.

It turns out that "1980 Stat Boundary" is nothing more than an alley. The photo below shows the portion which goes north from the 2800 block of Fulton.

Please... use the link at the bottom of this article (yellow section) to comment if you know the meaning of "1980 Stat Boundary."

Compiled by Neil Gale, Ph.D.