UA 3902 then AA 6256 at O'Hare
Rio De Janeiro → Chicago → Sioux Falls
Timetable, Chicago time
17:01UA 3902 from Rio De Janeiro at the gate
16:47AA 6256 to Sioux Falls leaves the gate
23 h 46 apart on the timetable, overnight
AA 6256 leaves 23 h 46 after UA 3902 arrives on the timetable: more than half a day, so not a connection we count.