AA 3960 then UA 3376 at O'Hare
Valparaiso → Chicago → St Louis
Timetable, Chicago time
14:34AA 3960 from Valparaiso at the gate
11:00UA 3376 to St Louis leaves the gate
20 h 26 apart on the timetable, overnight
UA 3376 leaves 20 h 26 after AA 3960 arrives on the timetable: more than half a day, so not a connection we count.