AA 9908 then UA 5517 at O'Hare
Milwaukee → Chicago → Tucson
Timetable, Chicago time
13:50AA 9908 from Milwaukee at the gate
08:50UA 5517 to Tucson leaves the gate
19 h apart on the timetable, overnight
UA 5517 leaves 19 h after AA 9908 arrives on the timetable: more than half a day, so not a connection we count.