UA 1623 then UA 2278 at San Francisco
Sacramento → San Francisco → Chicago O'Hare
Timetable, San Francisco time
07:15UA 1623 from Sacramento at the gatealso AC 4541, VA 8267, NZ 9676
22:45UA 2278 to Chicago O'Hare leaves the gatealso VA 8105
15 h 30 apart on the timetable
UA 2278 leaves 15 h 30 after UA 1623 arrives on the timetable: more than half a day, so not a connection we count.