Chicago, Illinois (a.k.a. Old Chicago in the 25th century) is the birthplace of William "Buck" Rogers (BR25: Film, "Awakening", "The Guardians").
Following the events of World War III, Chicago befell the fate of other metropolitan cities of the time period in a period known as the Holocaust, becoming ruins known in the 25th century as "Anarchia" (BR25: Film, "Awakening").
Following Rogers return to Earth in 2491 CE, and aided by Twiki and Dr. Theopolis, investigate the ruins of Chicago as Rogers wishes to seek closure regarding the fate of his loved ones. On State Street, he discovers a mass family grave with a singular marker, noting only the names of the buried (BR25: Film, "Awakening").
Old Chicago is mis-remembered by way of the Old Chicago Shopping Mall with a melange of different regional affectations of various Earth locales, derived and reconstructed from surviving artifacts (BR25: "A Dream of Jennifer").