Chicago is a much cleaner city. No comparison with New Haven, NYC (where I used to live), Philly (where I live now) or really anywhere else on the east coast. The culture of throwing trash on the ground is endemic on the east coast.

I was flying from NYC to Denver a few months ago and a Denverite and I struck up a conversation on this very topic after observing multiple people throwing trash on the floor in LGA. Speaking of which, Denver, another city that is much cleaner than anywhere on the east coast.