AA 1200 then UA 3376 at O'Hare
Washington National → Chicago → St Louis
Timetable, Chicago time
11:34AA 1200 from Washington National at the gate
11:00UA 3376 to St Louis leaves the gate
23 h 26 apart on the timetable, overnight
UA 3376 leaves 23 h 26 after AA 1200 arrives on the timetable: more than half a day, so not a connection we count.