AA 9909 then UA 2638 at O'Hare
Waterloo → Chicago → Houston
Timetable, Chicago time
17:10AA 9909 from Waterloo at the gate
10:34UA 2638 to Houston leaves the gate
17 h 24 apart on the timetable, overnight
UA 2638 leaves 17 h 24 after AA 9909 arrives on the timetable: more than half a day, so not a connection we count.