AA 9950 then UA 1555 at O'Hare
Charlotte → Chicago → Oklahoma City
Timetable, Chicago time
08:30AA 9950 from Charlotte at the gate
21:25UA 1555 to Oklahoma City leaves the gate
12 h 55 apart on the timetable
UA 1555 leaves 12 h 55 after AA 9950 arrives on the timetable: more than half a day, so not a connection we count.