UA 3922 then AA 1487 at O'Hare
Savannah → Chicago → San Antonio
Timetable, Chicago time
02:36UA 3922 from Savannah at the gate
20:53AA 1487 to San Antonio leaves the gate
18 h 17 apart on the timetable
AA 1487 leaves 18 h 17 after UA 3922 arrives on the timetable: more than half a day, so not a connection we count.