UA 2091 then FX 9791 at O'Hare
San Francisco → Chicago → Anchorage
Timetable, Chicago time
12:59UA 2091 from San Francisco at the gate
04:00FX 9791 to Anchorage leaves the gate
15 h 01 apart on the timetable, overnight
FX 9791 leaves 15 h 01 after UA 2091 arrives on the timetable: more than half a day, so not a connection we count.