An excerpt from an 1890 book on horse training.
This excerpt comes from Horse education: A Treatise on the Origin, Characteristics, and Training of Horses by Thomas J. Murray. Murray describes the origins of the modern horse, which he traces back to fossils of a prehistoric animal with three toes and a hoof from the Cretaceous period around 145 millions year ago. The modern horses of Mexico, South America, and North America can all be traced back to European colonization.