UA 745 then BR 643 at O'Hare
Atlanta → Chicago → Anchorage
Timetable, Chicago time
14:29UA 745 from Atlanta at the gate
11:55BR 643 to Anchorage leaves the gate
21 h 26 apart on the timetable, overnight
BR 643 leaves 21 h 26 after UA 745 arrives on the timetable: more than half a day, so not a connection we count.