UA 3878 then UA 787 at Houston
IAB → Houston → Chicago
Timetable, Houston time
22:40UA 3878 from IAB at the gate
13:40UA 787 to Chicago leaves the gate
15 h apart on the timetable, overnight
UA 787 leaves 15 h after UA 3878 arrives on the timetable: more than half a day, so not a connection we count.