Originally Posted by
milepig
No need to look for an "official link" except for flights from Canada, where you clear in CA, you need to recheck your bags at every single US airport when transiting INTL/Domestic. It's just the way the system works.
Yep. Even thought DTW has customs, the system is simply not setup to route your bag to the international/customs at DTW and for you to be able to go there and get it. Your bag will be tagged to DTW, but you'll have to pick it up at ORD, go through customs, then drop it at the recheck desk.