AA 899 then UA 5940 at O'Hare
Los Angeles → Chicago → Tucson
Timetable, Chicago time
06:00AA 899 from Los Angeles at the gate
19:54UA 5940 to Tucson leaves the gate
13 h 54 apart on the timetable
UA 5940 leaves 13 h 54 after AA 899 arrives on the timetable: more than half a day, so not a connection we count.