Originally Posted by WRCSolberg

You go through immigration in Ireland, or in my case it was Dublin. I landed at the international terminal at ORD and still had to go through the customs hall, albeit they fasttrack you through immigration such that you don't talk to anyone, you just go straight to the baggage claim.

After you claim your baggage you take your card which was stamped by immigration in Ireland to the traditional customs officer and you're done.