UA 4003 then UA 3263 at Houston
Memphis → Houston → Richmond
Timetable, Houston time
10:57UA 4003 from Memphis at the gate
07:00UA 3263 to Richmond leaves the gate
20 h 03 apart on the timetable, overnight
UA 3263 leaves 20 h 03 after UA 4003 arrives on the timetable: more than half a day, so not a connection we count.