Nomenclature
The term "horse whispering" dates to nineteenth century Europe when an Irish horseman, Daniel "Horse-Whisperer" Sullivan (d. 1810), made a name for himself in England by rehabilitating horses that had become vicious and intractable due to abuse or accidental trauma. Some natural horsemanship practitioners do not use the term "horse whisperer" to describe themselves, some horse trainers dislike the "horse whispering" moniker to the extent that they openly ask that the term not be applied to them.
"Natural horsemanship" is a later term, originating in the western United States, and not coming in to popular use around 1985. The term became linked to "horse whispering" in the 1990s, when the popularity of Nicholas Evans' book The Horse Whisperer, and the later Robert Redford film of the same name, promoted popular awareness of natural horsemanship. However, some trainers linked to the movement, such as Mark Rashid, have stated their discomfort with the term "natural horsemanship."
Read more about this topic: Natural Horsemanship