UA 3920 then AA 2612 at Houston
Orlando → Houston → Chicago
Timetable, Houston time
19:47UA 3920 from Orlando at the gate
17:11AA 2612 to Chicago leaves the gate
21 h 24 apart on the timetable, overnight
AA 2612 leaves 21 h 24 after UA 3920 arrives on the timetable: more than half a day, so not a connection we count.