UA 6235 then UA 3263 at Houston
Tucson → Houston → Richmond
Timetable, Houston time
15:35UA 6235 from Tucson at the gate
07:00UA 3263 to Richmond leaves the gate
15 h 25 apart on the timetable, overnight
UA 3263 leaves 15 h 25 after UA 6235 arrives on the timetable: more than half a day, so not a connection we count.