Of interest, this line was a former Maine Central that hosted the Bar Harbor Express, which had through (all-Pullman) Phila-Rockland car lines.
The Bar Harbor was a Summer only train that operated Phila-Bar Harbor (Bar Harbor ME was sort of "Philly-East"). The service was cut back to Ellsworth (on the mainland) and then further to Bangor. As I recall, it hung on until fairly late in the game with the "Adios" drumhead going up about 1965.