Terminology

When is it correct to say “railroad,” ditto “railway?”
Is either more proper in usage at certain times over the other choice?

The two terms are completely interchangeable in U.S. practice. In Canada, railway is the more common name for the corporate title. U.S. corporate titles often switched from one to the other to differentiate a company post-reorganization without having to change what the common (that is, public) name. At present, most Class Is in the U.S. are railways, but that’s just coincidence.

There are only three corporate titles that are “Rail Road” (two words) that I’m aware of: Long Island, Indiana, and Strasburg. Undoubtedly there are others.

A few U.S. railroads used the seemingly canadian and european name railway, I know of the Southern Railway and the Burlington Northern Santa Fe Railway. Mark is a tough act to follow with his weath of knowledge but I hope this helps.

In unofficial usage, it appears that most folk in the U.S. use the term railroad rather than railway. Would the “up over” folk agree?
Here down under , most poeple would refer to a railway rather than railroad.
For example, maps produced here usually say railway in the key/legend.

Dave
(Kozzie)

Canadian Pacific Railway
Southern British Columbia Railway

and

CN

that refuses to be called Canadian National Railway.

It’s just CN.