Answer:
Horses introduced by European traders changed the lifestyles of American Indians living on the Great Plains
Explanation:
The introduction of Horses in the Great Plains by the European trader Hernan Cortes was made in the year 1519. The Great Plains were spread from east of Rocky Mountains to 400 miles of plain land at the center of USA.
The American Indians in the plains hunted bigger animals by foot before the introduction of the horses.
In 1600, with the wide availability of the horses the inhabitants of the plains opted for buffalo-hunting giving up the agricultural lifestyle.
