I am interested is learning as much as possible about the Erie RR, especially the NY Division from Harriman to Port Jervis, from inception to today. What books would you recommend that I look for?
A good primer (very thorough) about the inception and management of the Erie (and subsequently, the EL) would be 'Erie Lackawanna: Death of an American Railroad 1938-1992', by H. Rogers Grant.
It's light on operations, but it answers many questions about why the Erie was as weak as it was.
-Micah