For those interested in such things, I have been trying to map Twain's 
travels associated with his 1868-69 American Vandals Tour.  The 
University of Nebraska has a collection of kmz files for railroads up to 
1870 and it is these that I have most relied on.  Many segments don't 
have names and many are approximations of routes.  It's not possible to 
accurately compare these with the USGS maps of the regions as the 
government maps are more recent and railroad companies have been 
unstable in regards to ownership and locations.  Many of these reported 
railroads do not seem to be known to Google.

I have often seen remarks on Mark Twain becoming fatigued/disenchanted 
with touring.  Examining these maps may provide some indication just why 
this happened.  He covered a lot of miles.  I have divided the tour up 
into 6 arbitrary sections for my Twain's Geography site, mainly to 
lessen confusion with the maps.