AA 4649 then DL 2570 at O'Hare
Pittsburgh → Chicago → Boston
Timetable, Chicago time
11:00AA 4649 from Pittsburgh at the gate
10:35DL 2570 to Boston leaves the gate
23 h 35 apart on the timetable, overnight
DL 2570 leaves 23 h 35 after AA 4649 arrives on the timetable: more than half a day, so not a connection we count.