LA 6139 then AA 1954 at San Francisco
Boston → San Francisco → Chicago O'Hare
Timetable, San Francisco time
23:58LA 6139 from Boston at the gate
23:36AA 1954 to Chicago O'Hare leaves the gatealso QF 3241
23 h 38 apart on the timetable, overnight
AA 1954 leaves 23 h 38 after LA 6139 arrives on the timetable: more than half a day, so not a connection we count.