One further thought. If you look closely at the depot, you can see the shadows cast by the sunlight. The wall facing the tracks is in full sun. The light is just hitting the gable end at an angle, as you can tell by the shadow thrown by the deep eaves and the window cornice. Judging by the leaves on the trees it's summer. Now, given that the sun sets in the northwest in New England in midsummer, and given that the angle of the light seems right for 5:30 p.m. at that time of year, the track in this picture runs pretty much due N-S, with the train coming from S and the station on the E side of the ROW.
So- we're looking for a stretch of N-S double-track, on a line built between 1850 and 1870, with a station on the E side of the line, between a grade crossing and an overpass of some kind. And, since we know from the caption that this train is coming from Boston, and we know from the sunlight that the train is heading north, that implies the location is most likely north of Boston-- unless it's on some anomalous stretch of track that deviates from an E-W alignment for a couple miles, or reverses completely from the overall direction of the line.
Anybody got some detailed maps?