I wanted to like this as I've always been fascinated by the Pony Express. Most of it was quite good but I'm shocked to realize that it was published in 2003. It's fairly racist in places (for example referring to Native Americans as savages). It also glorifies the taking of land for the civilized peoples (i.e. white settlers). Disappointing. Look elsewhere for your history.
Updated: I've just realized this was written by a historian who died in 1930, so unfortunately his language and attitude are par for the course for his time. It's still irritating.