UA 3902 then B6 112 at O'Hare
Rio De Janeiro → Chicago → Boston
Timetable, Chicago time
17:01UA 3902 from Rio De Janeiro at the gate
13:00B6 112 to Boston leaves the gate
19 h 59 apart on the timetable, overnight
B6 112 leaves 19 h 59 after UA 3902 arrives on the timetable: more than half a day, so not a connection we count.