UA 3851 then UA 1147 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
15:20UA 1147 to Chicago O'Hare leaves the gatealso AC 4185, CA 7326, VA 8104, NZ 9313
21 h 39 apart on the timetable, overnight
UA 1147 leaves 21 h 39 after UA 3851 arrives on the timetable: more than half a day, so not a connection we count.