Railroad People (A Children's Train Book) by Joyce A. Mills
On the Right Track: Through the Eyes of a Locomotive Engineer by Joyce A Mills
Rockville Bridge: Rails Across the Susquehanna by Dan Cupper 
The People's Bridge: A History of the Walnut Street Bridge Harrisburg to Wormleysburg by Dan Cupper and 
Horseshoe Heritage by Dan Cupper.

The Used Railroad books are at the following link and in the store: Online Railroad Books