UA 3375 then UA 3378 at O'Hare
St Louis → Chicago → Richmond
Timetable, Chicago time
09:30UA 3375 from St Louis at the gate
08:30UA 3378 to Richmond leaves the gate
23 h apart on the timetable, overnight
UA 3378 leaves 23 h after UA 3375 arrives on the timetable: more than half a day, so not a connection we count.