AA 2504 then UA 5191 at O'Hare
Houston → Chicago → Lancaster
Timetable, Chicago time
14:15AA 2504 from Houston at the gate
08:50UA 5191 to Lancaster leaves the gate
18 h 35 apart on the timetable, overnight
UA 5191 leaves 18 h 35 after AA 2504 arrives on the timetable: more than half a day, so not a connection we count.