AA 9950 then UA 5749 at O'Hare
Philadelphia → Chicago → Madison
Timetable, Chicago time
13:49AA 9950 from Philadelphia at the gate
10:35UA 5749 to Madison leaves the gate
20 h 46 apart on the timetable, overnight
UA 5749 leaves 20 h 46 after AA 9950 arrives on the timetable: more than half a day, so not a connection we count.