UA 3902 then AA 3486 at O'Hare
Rio De Janeiro → Chicago → Jacksonville
Timetable, Chicago time
17:01UA 3902 from Rio De Janeiro at the gate
08:13AA 3486 to Jacksonville leaves the gate
15 h 12 apart on the timetable, overnight
AA 3486 leaves 15 h 12 after UA 3902 arrives on the timetable: more than half a day, so not a connection we count.