AA 865 then UA 5191 at O'Hare
Philadelphia → Chicago → Lancaster
Timetable, Chicago time
12:18AA 865 from Philadelphia at the gate
08:50UA 5191 to Lancaster leaves the gate
20 h 32 apart on the timetable, overnight
UA 5191 leaves 20 h 32 after AA 865 arrives on the timetable: more than half a day, so not a connection we count.