AA 9950 then AA 3974 at O'Hare
Philadelphia → Chicago → Harrisburg
Timetable, Chicago time
13:49AA 9950 from Philadelphia at the gate
10:35AA 3974 to Harrisburg leaves the gate
20 h 46 apart on the timetable, overnight
AA 3974 leaves 20 h 46 after AA 9950 arrives on the timetable: more than half a day, so not a connection we count.