UA 3922 then AA 6246 at O'Hare
Savannah → Chicago → Nashville
Timetable, Chicago time
02:36UA 3922 from Savannah at the gate
15:05AA 6246 to Nashville leaves the gate
12 h 29 apart on the timetable
AA 6246 leaves 12 h 29 after UA 3922 arrives on the timetable: more than half a day, so not a connection we count.