LA 6139 then AA 1854 at San Francisco
Boston → San Francisco → Chicago O'Hare
Timetable, San Francisco time
23:58LA 6139 from Boston at the gate
23:39AA 1854 to Chicago O'Hare leaves the gatealso QF 4325, PD 6392, EI 7107
23 h 41 apart on the timetable, overnight
AA 1854 leaves 23 h 41 after LA 6139 arrives on the timetable: more than half a day, so not a connection we count.