F9 1595 then UA 3376 at O'Hare
Atlanta → Chicago → St Louis
Timetable, Chicago time
18:30F9 1595 from Atlanta at the gate
11:00UA 3376 to St Louis leaves the gate
16 h 30 apart on the timetable, overnight
UA 3376 leaves 16 h 30 after F9 1595 arrives on the timetable: more than half a day, so not a connection we count.