AA 9908 then UA 5790 at O'Hare
Milwaukee → Chicago → St Louis
Timetable, Chicago time
13:50AA 9908 from Milwaukee at the gate
13:00UA 5790 to St Louis leaves the gate
23 h 10 apart on the timetable, overnight
UA 5790 leaves 23 h 10 after AA 9908 arrives on the timetable: more than half a day, so not a connection we count.