UA 2638 then UA 3263 at Houston
Chicago → Houston → Richmond
Timetable, Houston time
13:35UA 2638 from Chicago at the gate
07:00UA 3263 to Richmond leaves the gate
17 h 25 apart on the timetable, overnight
UA 3263 leaves 17 h 25 after UA 2638 arrives on the timetable: more than half a day, so not a connection we count.