DL 420 then AA 6255 at O'Hare
Savannah → Chicago → Sioux Falls
Timetable, Chicago time
13:13DL 420 from Savannah at the gate
13:02AA 6255 to Sioux Falls leaves the gate
23 h 49 apart on the timetable, overnight
AA 6255 leaves 23 h 49 after DL 420 arrives on the timetable: more than half a day, so not a connection we count.