Possible Clues:

• A port in Illinois
• Average Town, U.S.A
• Midwest city representing average tastes
• 'But will it play in ___?'
• Hometown of old radio's Fibber McGee and Molly
• Illinois birthplace of Richard Pryor and Betty Friedan
• Caterpillar's home city
• Famously mainstream American town
• Everytown, USA
• America's Everytown