I don't believe any DET-CHI trains have checked baggage (but I could be wrong), so all baggage would have to hand carried. You may see a checked baggage counter in DET, and certainly in CHI, but they will not (probably) be for your trains.

If you want to lower your costs, you may want to check out the "Weekly Specials" page on the Amtrak.com website. (The savings may be 50-80%! ) Many times, there are trains listed from CHI-DET. (There is this week! ) If the dates and times agree with you, you may want to go for this. But remember - there are only a certain number of seats at that special price, and it is in coach!

Also check the 2007 Promotions and Discounts sticky at the top of this forum. You may see some promo code that may save youu some money!