I have a good friend flying LHR-ORD in October who is not a frequent flier and as this is his first visit to the USA I want to give him some advice on arrivals etc.

He's on the 1215 AA flight on the 17th and he's completed ESTA with no problems.

My last flight into ORD was from BHX in 1996, so if anyone can offer any insights from somewhat more recent experience(!) that would help someone new to all this nonsense I'd be very grateful. Thanks.