DL 2898 then UA 4500 at Detroit
Buffalo → Detroit → Washington
Timetable, Detroit time
07:27DL 2898 from Buffalo at the gate
19:45UA 4500 to Washington leaves the gate
12 h 18 apart on the timetable
UA 4500 leaves 12 h 18 after DL 2898 arrives on the timetable: more than half a day, so not a connection we count.