UA 3920 then UA 4050 at Houston
Orlando → Houston → Louisville
Timetable, Houston time
19:47UA 3920 from Orlando at the gate
17:10UA 4050 to Louisville leaves the gate
21 h 23 apart on the timetable, overnight
UA 4050 leaves 21 h 23 after UA 3920 arrives on the timetable: more than half a day, so not a connection we count.