CV 12 then UA 4518 at O'Hare
Anchorage → Chicago → St Louis
Timetable, Chicago time
19:11CV 12 from Anchorage at the gate
16:35UA 4518 to St Louis leaves the gate
21 h 24 apart on the timetable, overnight
UA 4518 leaves 21 h 24 after CV 12 arrives on the timetable: more than half a day, so not a connection we count.