AA 2504 then BR 643 at O'Hare
Houston → Chicago → Anchorage
Timetable, Chicago time
14:15AA 2504 from Houston at the gate
11:55BR 643 to Anchorage leaves the gate
21 h 40 apart on the timetable, overnight
BR 643 leaves 21 h 40 after AA 2504 arrives on the timetable: more than half a day, so not a connection we count.