As far as I remember, Chicago with AA involves a terminal change. You should make it in 1h55, but you will have a long walk from the plane through the terminal to immigration (which you can skip since you did it in Ireland first), then you have to wait for your bags - I have waited 15-20 minutes for this before, pass through Customs and the Department of Food or whatever check which *could* take a long time if there are other planes in at the same time. Then you have to drop the bags again (not a long process - you literally drop them) and find and get the train to the other terminal. *Then* you have to queue to get through security again along with 'the public' and as with any airport queue this could also be a significant time. As above you should make it and since you are booked on a through ticket, even if you miss it you should be accommodated on a later flight, but don't under-estimate the time it takes to get through the process.
At least in Newark you don't have to change terminal but you still have all the rest of the delays. I understand that there is a plan to move customs processing to Dublin (or it might have been Shannon) so this would mean you get off the plane in the US, stay airside, and go to your next gate, skipping the customs queue, the baggage pickup and drop off queue and the security screening queue. This will make a major dent in the time taken between planes.
z