UA 1008 then AA 3974 at O'Hare
New York LaGuardia → Chicago → Harrisburg
Timetable, Chicago time
09:01UA 1008 from New York LaGuardia at the gate
08:27AA 3974 to Harrisburg leaves the gate
23 h 26 apart on the timetable, overnight
AA 3974 leaves 23 h 26 after UA 1008 arrives on the timetable: more than half a day, so not a connection we count.