AA 6249 then DL 2570 at O'Hare
Kansas City → Chicago → Boston
Timetable, Chicago time
11:05AA 6249 from Kansas City at the gate
10:35DL 2570 to Boston leaves the gate
23 h 30 apart on the timetable, overnight
DL 2570 leaves 23 h 30 after AA 6249 arrives on the timetable: more than half a day, so not a connection we count.