AA 3096 then UA 3376 at O'Hare
Salt Lake City → Chicago → St Louis
Timetable, Chicago time
16:05AA 3096 from Salt Lake City at the gate
11:00UA 3376 to St Louis leaves the gate
18 h 55 apart on the timetable, overnight
UA 3376 leaves 18 h 55 after AA 3096 arrives on the timetable: more than half a day, so not a connection we count.