B6 663 then UA 3376 at O'Hare
Fort Lauderdale → Chicago → St Louis
Timetable, Chicago time
13:42B6 663 from Fort Lauderdale at the gate
11:00UA 3376 to St Louis leaves the gate
21 h 18 apart on the timetable, overnight
UA 3376 leaves 21 h 18 after B6 663 arrives on the timetable: more than half a day, so not a connection we count.