AA 6366 then UA 3914 at O'Hare
Waterloo → Chicago → Houston
Timetable, Chicago time
07:39AA 6366 from Waterloo at the gate
20:30UA 3914 to Houston leaves the gate
12 h 51 apart on the timetable
UA 3914 leaves 12 h 51 after AA 6366 arrives on the timetable: more than half a day, so not a connection we count.