AA 4918 then UA 3376 at O'Hare
Colorado Springs → Chicago → St Louis
Timetable, Chicago time
17:29AA 4918 from Colorado Springs at the gate
11:00UA 3376 to St Louis leaves the gate
17 h 31 apart on the timetable, overnight
UA 3376 leaves 17 h 31 after AA 4918 arrives on the timetable: more than half a day, so not a connection we count.