UA 3450 then AA 5543 at Charlotte
Chicago O'Hare → Charlotte → Pittsburgh
Timetable, Charlotte time
13:42UA 3450 from Chicago O'Hare at the gate
08:30AA 5543 to Pittsburgh leaves the gate
18 h 48 apart on the timetable, overnight
AA 5543 leaves 18 h 48 after UA 3450 arrives on the timetable: more than half a day, so not a connection we count.