UA 4619 then BR 643 at O'Hare
Buffalo → Chicago → Anchorage
Timetable, Chicago time
11:43UA 4619 from Buffalo at the gate
11:25BR 643 to Anchorage leaves the gate
23 h 42 apart on the timetable, overnight
BR 643 leaves 23 h 42 after UA 4619 arrives on the timetable: more than half a day, so not a connection we count.