AA 2258 then BR 643 at O'Hare
Las Vegas → Chicago → Anchorage
Timetable, Chicago time
12:52AA 2258 from Las Vegas at the gate
11:55BR 643 to Anchorage leaves the gate
23 h 03 apart on the timetable, overnight
BR 643 leaves 23 h 03 after AA 2258 arrives on the timetable: more than half a day, so not a connection we count.