AA 3487 then UA 5940 at O'Hare
Missoula → Chicago → Peoria
Timetable, Chicago time
18:25AA 3487 from Missoula at the gate
16:40UA 5940 to Peoria leaves the gate
22 h 15 apart on the timetable, overnight
UA 5940 leaves 22 h 15 after AA 3487 arrives on the timetable: more than half a day, so not a connection we count.