UA 4774 then AA 9912 at O'Hare
Tucson → Chicago → Richmond
Timetable, Chicago time
13:02UA 4774 from Tucson at the gate
07:30AA 9912 to Richmond leaves the gate
18 h 28 apart on the timetable, overnight
AA 9912 leaves 18 h 28 after UA 4774 arrives on the timetable: more than half a day, so not a connection we count.