AA 9867 then UA 4572 at O'Hare
Marquette → Chicago → Sioux Falls
Timetable, Chicago time
13:05AA 9867 from Marquette at the gate
12:29UA 4572 to Sioux Falls leaves the gate
23 h 24 apart on the timetable, overnight
UA 4572 leaves 23 h 24 after AA 9867 arrives on the timetable: more than half a day, so not a connection we count.