AA 3539 then UA 3376 at O'Hare
Moline → Chicago → St Louis
Timetable, Chicago time
12:36AA 3539 from Moline at the gate
11:00UA 3376 to St Louis leaves the gate
22 h 24 apart on the timetable, overnight
UA 3376 leaves 22 h 24 after AA 3539 arrives on the timetable: more than half a day, so not a connection we count.