UA 3902 then AA 2254 at O'Hare
Rio De Janeiro → Chicago → New York LaGuardia
Timetable, Chicago time
17:01UA 3902 from Rio De Janeiro at the gate
11:05AA 2254 to New York LaGuardia leaves the gate
18 h 04 apart on the timetable, overnight
AA 2254 leaves 18 h 04 after UA 3902 arrives on the timetable: more than half a day, so not a connection we count.