AA 4102 then FX 9791 at O'Hare
Denver → Chicago → Anchorage
Timetable, Chicago time
12:55AA 4102 from Denver at the gate
04:00FX 9791 to Anchorage leaves the gate
15 h 05 apart on the timetable, overnight
FX 9791 leaves 15 h 05 after AA 4102 arrives on the timetable: more than half a day, so not a connection we count.