UA 6213 then UA 3263 at Houston
St Louis → Houston → Richmond
Timetable, Houston time
13:24UA 6213 from St Louis at the gate
07:00UA 3263 to Richmond leaves the gate
17 h 36 apart on the timetable, overnight
UA 3263 leaves 17 h 36 after UA 6213 arrives on the timetable: more than half a day, so not a connection we count.