UA 3922 then AA 3222 at O'Hare
Savannah → Chicago → Baltimore
Timetable, Chicago time
02:36UA 3922 from Savannah at the gate
21:00AA 3222 to Baltimore leaves the gate
18 h 24 apart on the timetable
AA 3222 leaves 18 h 24 after UA 3922 arrives on the timetable: more than half a day, so not a connection we count.