AA 9950 then AA 4757 at O'Hare
Philadelphia → Chicago → Pittsburgh
Timetable, Chicago time
13:49AA 9950 from Philadelphia at the gate
09:46AA 4757 to Pittsburgh leaves the gate
19 h 57 apart on the timetable, overnight
AA 4757 leaves 19 h 57 after AA 9950 arrives on the timetable: more than half a day, so not a connection we count.