UA 3920 then AA 2645 at Houston
Orlando → Houston → Chicago
Timetable, Houston time
19:47UA 3920 from Orlando at the gate
14:32AA 2645 to Chicago leaves the gate
18 h 45 apart on the timetable, overnight
AA 2645 leaves 18 h 45 after UA 3920 arrives on the timetable: more than half a day, so not a connection we count.