BR 642 then UA 3487 at O'Hare
Anchorage → Chicago → Key West
Timetable, Chicago time
11:55BR 642 from Anchorage at the gate
11:00UA 3487 to Key West leaves the gate
23 h 05 apart on the timetable, overnight
UA 3487 leaves 23 h 05 after BR 642 arrives on the timetable: more than half a day, so not a connection we count.