UA 3884 then AA 3768 at O'Hare
Melbourne (Florida) → Chicago → St Louis
Timetable, Chicago time
01:06UA 3884 from Melbourne (Florida) at the gate
20:50AA 3768 to St Louis leaves the gate
19 h 44 apart on the timetable
AA 3768 leaves 19 h 44 after UA 3884 arrives on the timetable: more than half a day, so not a connection we count.