F9 1596 then DL 865 at Atlanta
Chicago O'Hare → Atlanta → Boston
Timetable, Atlanta time
10:30F9 1596 from Chicago O'Hare at the gate
22:40DL 865 to Boston leaves the gate
12 h 10 apart on the timetable
DL 865 leaves 12 h 10 after F9 1596 arrives on the timetable: more than half a day, so not a connection we count.