AA 9908 then UA 1606 at O'Hare
Milwaukee → Chicago → Boston
Timetable, Chicago time
13:50AA 9908 from Milwaukee at the gate
10:30UA 1606 to Boston leaves the gate
20 h 40 apart on the timetable, overnight
UA 1606 leaves 20 h 40 after AA 9908 arrives on the timetable: more than half a day, so not a connection we count.