AA 2925 then CA 3174 at O'Hare
Boston → Chicago → Guangzhou
Timetable, Chicago time
21:54AA 2925 from Boston at the gate
13:40CA 3174 to Guangzhou leaves the gate
15 h 46 apart on the timetable, overnight
CA 3174 leaves 15 h 46 after AA 2925 arrives on the timetable: more than half a day, so not a connection we count.