AA 1954 then UA 1646 at San Francisco
Chicago O'Hare → San Francisco → Baltimore
Timetable, San Francisco time
21:56AA 1954 from Chicago O'Hare at the gatealso GF 6444
21:30UA 1646 to Baltimore leaves the gatealso NZ 9032
23 h 34 apart on the timetable, overnight
UA 1646 leaves 23 h 34 after AA 1954 arrives on the timetable: more than half a day, so not a connection we count.