DL 420 then AA 4400 at O'Hare
Savannah → Chicago → Memphis
Timetable, Chicago time
13:13DL 420 from Savannah at the gate
11:50AA 4400 to Memphis leaves the gate
22 h 37 apart on the timetable, overnight
AA 4400 leaves 22 h 37 after DL 420 arrives on the timetable: more than half a day, so not a connection we count.