AA 9866 then AA 861 at O'Hare
Marquette → Chicago → Hartford
Timetable, Chicago time
10:30AA 9866 from Marquette at the gate
08:21AA 861 to Hartford leaves the gate
21 h 51 apart on the timetable, overnight
AA 861 leaves 21 h 51 after AA 9866 arrives on the timetable: more than half a day, so not a connection we count.