AA 9866 then UA 1606 at O'Hare
Bloomington-Normal → Chicago → Boston
Timetable, Chicago time
13:11AA 9866 from Bloomington-Normal at the gate
10:30UA 1606 to Boston leaves the gate
21 h 19 apart on the timetable, overnight
UA 1606 leaves 21 h 19 after AA 9866 arrives on the timetable: more than half a day, so not a connection we count.