I have read that horses were native to North America but went extinct over 10,000 years ago. The horse was reintroduced to North America, from what I can find, by the Spaniards. Were the Native Americans portrayed in the movie using horses that were reintroduced to North America by the Spaniards? Did the Natives think they were wild horses or did they benefit from something the white man brought and they didn't even know it? Horses are used quite a bit in the movie Dances with Wolves, and they look like they were a part of their lives for quite some time since they maintained a heard of them, used them to hunt and for transportation. Are the horses portrayed in the movie Dances with Wolves indigenous horses or are they horses that had made their way across the land unbeknownst to the Native Americans?
By the time period Dances with Wolves was set (late 19th century), Horses had been in that part of the west for more than a hundred years. Natives knew horses weren't native because their grandfathers and great-grandfathers would have remembered them arriving. Those farther south would have known they were captured from the Spanish after the Pueblo revolt, where many of the wild herds came from.