Originally Posted by knope2001

Another possible option is fly into O'Hare or Midway, take the CTA down to the loop, and board Amtrak for Kalamazoo or Grand Rapids.

O'Hare CTA Blue line departs right from ORD and stops within about two blocks of Union Station.

or

Midway CTA Orange line depart right from from MDW and stops within about four blocks of Union Station.

I believe CTA is $2 each way, and Amtrak to Kalamazoo is something around twenty bucks or a little less.