Hmm, see what you mean, try this one - http://www.railwaystays.com/luxury-trains-worldwide/africa/rovos-rail/
Yes and of course the fact that there are huge swathes of the country - inc a few entire states - without a service prob doesn't exactly encourage domestic train travel. Plus a lively road and air lobby there no doubt shouts considerably louder than Amtrak's advocates. It's a real shame, for example, that your only trans-continental service has been cut back, now only going as far as New Orleans, despite the track being repaired years ago, now used only by freights. Still I'm sure it's going to be an epic trip! :)
thanks :)