AA 9866 then ET 575 at O'Hare
Marquette → Chicago → Addis Ababa
Timetable, Chicago time
10:30AA 9866 from Marquette at the gate
09:45ET 575 to Addis Ababa leaves the gate
23 h 15 apart on the timetable, overnight
ET 575 leaves 23 h 15 after AA 9866 arrives on the timetable: more than half a day, so not a connection we count.