The flight was 3 hours late to leave from Atlanta due to some maintenance issue. We arrived 3 hours late and we missed all the international flights afterwards. We arrived to Chicago close to midnight and there was no one to help out, the pilots/flight attendants seemed amused that we missed our connecting flight due to their flight being late. They gave number to call which was a pain, a lot of being on hold and they hand up twice on me. The flight they offered to re-book would leave Chicago 2 days later. Since we were going to wedding and that was our hard earned vacation we couldn't afford that. In the end, we got different flight by British Airways. Beware when flying AA!