"Charlestown" is apparently where the penitentiary is located. Why Charlestown would be reached by an "east-bound" train is a bit of a puzzle but if you go east for enough you should be able to reach Charlestown via the great circle route, although the "iron chains" might get a little rusty by then.

I always envisioned the line about his aged father "standing at the bar" having reference to how he choose to console himself. However, the line about his aged mother "just tearing out her old gray locks with the tears all streaming down" seemed particularly poignant, no one in the band could keep a straight face. Of course at that time none of us had any gray hairs to speak of.

Cheerily,
Charley Noble