Chicago's municipal device, the Y symbol.
https://www.wbez.org/stories/_/fd9cf47b-904e-4654-ad06-ff7fc8727758
https://forgottenchicago.com/articles/the-municipal-device/
https://chicago-outdoor-sculptures.blogspot.com/2010/01/y-symbol.html
Chicago's municipal device, the Y symbol.
https://www.wbez.org/stories/_/fd9cf47b-904e-4654-ad06-ff7fc8727758
https://forgottenchicago.com/articles/the-municipal-device/
https://chicago-outdoor-sculptures.blogspot.com/2010/01/y-symbol.html