AA 5255 then DL 1556 at O'Hare
Dayton → Chicago → Los Angeles
Timetable, Chicago time
08:43AA 5255 from Dayton at the gate
07:45DL 1556 to Los Angeles leaves the gate
23 h 02 apart on the timetable, overnight
DL 1556 leaves 23 h 02 after AA 5255 arrives on the timetable: more than half a day, so not a connection we count.