AA 642 then UA 1225 at O'Hare
Dallas-Fort Worth → Chicago → Eugene
Timetable, Chicago time
13:10AA 642 from Dallas-Fort Worth at the gate
09:01UA 1225 to Eugene leaves the gate
19 h 51 apart on the timetable, overnight
UA 1225 leaves 19 h 51 after AA 642 arrives on the timetable: more than half a day, so not a connection we count.