UA 3902 then UA 1486 at Houston
Toronto → Houston → Chicago
Timetable, Houston time
08:27UA 3902 from Toronto at the gate
05:00UA 1486 to Chicago leaves the gate
20 h 33 apart on the timetable, overnight
UA 1486 leaves 20 h 33 after UA 3902 arrives on the timetable: more than half a day, so not a connection we count.