AA 4504 then UA 5199 at O'Hare
South Bend → Chicago → Denver
Timetable, Chicago time
18:35AA 4504 from South Bend at the gate
08:30UA 5199 to Denver leaves the gate
13 h 55 apart on the timetable, overnight
UA 5199 leaves 13 h 55 after AA 4504 arrives on the timetable: more than half a day, so not a connection we count.