UA 3902 then AA 4189 at O'Hare
Rio De Janeiro → Chicago → Missoula
Timetable, Chicago time
17:01UA 3902 from Rio De Janeiro at the gate
09:40AA 4189 to Missoula leaves the gate
16 h 39 apart on the timetable, overnight
AA 4189 leaves 16 h 39 after UA 3902 arrives on the timetable: more than half a day, so not a connection we count.