DL 1821 then AA 660 at Detroit
Portland (Maine) → Detroit → Dallas-Fort Worth
Timetable, Detroit time
18:58DL 1821 from Portland (Maine) at the gate
18:00AA 660 to Dallas-Fort Worth leaves the gate
23 h 02 apart on the timetable, overnight
AA 660 leaves 23 h 02 after DL 1821 arrives on the timetable: more than half a day, so not a connection we count.