UA 3501 then AA 4548 at O'Hare
Detroit → Chicago → Des Moines
Timetable, Chicago time
06:57UA 3501 from Detroit at the gate
22:53AA 4548 to Des Moines leaves the gate
15 h 56 apart on the timetable
AA 4548 leaves 15 h 56 after UA 3501 arrives on the timetable: more than half a day, so not a connection we count.