AA 3243 then AS 257 at Boston
Washington National → Boston → Seattle
Timetable, Boston time
16:40AA 3243 from Washington National at the gate
16:33AS 257 to Seattle leaves the gate
23 h 53 apart on the timetable, overnight
AS 257 leaves 23 h 53 after AA 3243 arrives on the timetable: more than half a day, so not a connection we count.