On April 22, 1519, the Spanish conquistador Hernán Cortés established the city of Veracruz in what is now Mexico. This began his conquest of the Aztec Empire, culminating with the fall of its capital Tenochtitlán in 1521. The horse played a crucial role in this victory by the Spaniards.

Cortés’s expedition marked the reintroduction of the horse on the mainland of North America up until this point, this land mass had not had horses for thousands of years.

For the 500th anniversary of the horse’s return to mainland North America, we interviewed Dr. Deb Bennett of the Equine Studies Institute. Through her career, she has studied this historic return of the horse and subsequent equine migration throughout the Western Hemisphere.

The Horse in North America Before 1519

The story of the horse’s return to North America predates Hernán Cortés or any explorer. Various ancestors to the domestic horse (Equus caballas) were thought to have roamed North America for millions of years. Then, somewhere between 8,000 to 12,000 years ago, the wild horse became extinct from North America.

Theories differ on what occurred to the ancient horse, pointing to the causes relating to climate change and overhunting by early ancestors of Native Americans. Archeologists differ on when humans first appeared in North America, with most theories ranging from 10,000 to 15,000 years ago. A more recent, controversial theory places that at 150,000 years ago. Nonetheless, there is no certainty on the emergence. Bennett believes overhunting was a major contributor.

“Among European…