UA 3851 then AA 3049 at San Francisco
Rio De Janeiro → San Francisco → Chicago O'Hare
Timetable, San Francisco time
17:41UA 3851 from Rio De Janeiro at the gate
13:42AA 3049 to Chicago O'Hare leaves the gatealso QF 3164, GF 6457, JL 7550
20 h 01 apart on the timetable, overnight
AA 3049 leaves 20 h 01 after UA 3851 arrives on the timetable: more than half a day, so not a connection we count.