AA 4400 then UA 5191 at O'Hare
Memphis → Chicago → Lancaster
Timetable, Chicago time
16:25AA 4400 from Memphis at the gate
08:50UA 5191 to Lancaster leaves the gate
16 h 25 apart on the timetable, overnight
UA 5191 leaves 16 h 25 after AA 4400 arrives on the timetable: more than half a day, so not a connection we count.