There’s a very useful section on transportation geography that’s useful for putting railroads in the larger transportation context in which they operated:
In most browsers you have a way to enlarge the screen magnification. Mine is set up so I hold CTRL, then roll the scroll wheel on my mouse to go bigger or smaller. Don’t remember how I set this up, but your browser should have a way to do this to enlarge within it. This won’t help any saved pics directly, but does make things bigger for viewing.