F9 1596 then DL 2642 at Atlanta
Chicago O'Hare → Atlanta → Philadelphia
Timetable, Atlanta time
10:30F9 1596 from Chicago O'Hare at the gate
22:54DL 2642 to Philadelphia leaves the gate
12 h 24 apart on the timetable
DL 2642 leaves 12 h 24 after F9 1596 arrives on the timetable: more than half a day, so not a connection we count.