UA 3922 then AA 1861 at O'Hare
Savannah → Chicago → San Diego
Timetable, Chicago time
02:36UA 3922 from Savannah at the gate
21:20AA 1861 to San Diego leaves the gate
18 h 44 apart on the timetable
AA 1861 leaves 18 h 44 after UA 3922 arrives on the timetable: more than half a day, so not a connection we count.