And 10 hours at some stations, IAH I think being one of them. Airlines in North America are just different in that respect.

This restriction is actually quite well known so I would suggest the OP check this out in the AA forum. It's certainly not the first time it has happened, the late LHR-JFKs giving particular issues for connections. When I give advice about BA's 24 hour rule I try to remember to point out that it doesn't apply to AA. There isn't any point complaining to either AA or BA about this.