UA 454 then AA 3974 at O'Hare
Orlando → Chicago → Harrisburg
Timetable, Chicago time
09:08UA 454 from Orlando at the gate
08:27AA 3974 to Harrisburg leaves the gate
23 h 19 apart on the timetable, overnight
AA 3974 leaves 23 h 19 after UA 454 arrives on the timetable: more than half a day, so not a connection we count.