The Shorpy site for old photographs has been putting up some great older railroad shots.
Here are the links to the site. Do not post these due to copyright but the links will take you right to the pictures.
In the roundhouse at an Illinois Central Railroad yard.
Tender and switch engine at an Illinois Central railyard.
An oil train from the Southwest leaves an Illinois Central railyard.
I would highly encourage you to browse Shorpy and check back daily for some great vintage photographs but don't post pictures here just links.