AA 4968 then AA 2151 at O'Hare
Birmingham (Alabama) → Chicago → Nashville
Timetable, Chicago time
09:00AA 4968 from Birmingham (Alabama) at the gate
21:10AA 2151 to Nashville leaves the gate
12 h 10 apart on the timetable
AA 2151 leaves 12 h 10 after AA 4968 arrives on the timetable: more than half a day, so not a connection we count.