UA 4554 then AA 9912 at O'Hare
Richmond → Chicago → Richmond
Timetable, Chicago time
09:33UA 4554 from Richmond at the gate
07:30AA 9912 to Richmond leaves the gate
21 h 57 apart on the timetable, overnight
AA 9912 leaves 21 h 57 after UA 4554 arrives on the timetable: more than half a day, so not a connection we count.