UA 3874 then AA 4682 at O'Hare
Chicago → Chicago → Dayton
Timetable, Chicago time
01:21UA 3874 from Chicago at the gate
15:30AA 4682 to Dayton leaves the gate
14 h 09 apart on the timetable
AA 4682 leaves 14 h 09 after UA 3874 arrives on the timetable: more than half a day, so not a connection we count.