UA 351 then AA 9912 at O'Hare
Washington National → Chicago → Richmond
Timetable, Chicago time
10:50UA 351 from Washington National at the gate
07:30AA 9912 to Richmond leaves the gate
20 h 40 apart on the timetable, overnight
AA 9912 leaves 20 h 40 after UA 351 arrives on the timetable: more than half a day, so not a connection we count.