Looking back once more into antiquity, we recall that the Childhood Home of the horse was North America. Mercilessly driven from this home by the the Illinoian Glaciation, 230,000 years ago, they had made their way into Europe and Asia. The coming of further Ice Ages had separated the horse family into large populations. Over the centuries of separation they had became more and more strangers to each other.
Eminent among all these, one branch of the horse family - the Spanish horse - had made its name in the Old World, was tired of roaming, and was ready to come home.
With the final defeat of the Moors in 1492, it could only be expected that Spanish Conquest of other lands would have begun. The Spanish wars of expansion would be waged by the thundering hooves of Spanish horses.
Columbus took no horses on his first voyage in 1492. On his second voyage
in 1493, by deceit 
and deception from his suppliers (and possibly on his own account to
get horses that would stand the test), took to
Hispañola the ancient Spanish Marismeños, the unchanged descendants of
the Cantabrican horses
isolated during the Würm Glaciation so many thousands of years before -
the most natural and hardy
horses in the world.
“ “When, in 1493, before his second voyage, Cristóbal Colón bought the horses that he desired to take to the Antilles, those that were shown to him in the Military Review in Seville, grand examples for war. It appears that these were grand Andalusian Chargers, rode with short stirrups, of those that fought in Granada. But, the individuals who were to put them on the ship maliciously substituted, at the moment of embarking, others than those that he had seen, sending to America small horses of inferior quality, very different from those that he had observed in the parade. (D. Fernando de Navarrete - Letters from Columbus referring to his second voyage to America.)”
“Thanks to this subterfuge, these Andalusian horses of those in the perfected herds of Granada, Cordoba, and Jerez, by that time possibly with Flemish cross, were replaced by horses raised in the environs of Palos and The Rabida - (Southern Spain – much marsh land - Palos de la Frontera, where Columbus found his crew) (La Rábida is where Columbus stayed between 1491-92 waiting for financial backing from the Catholic Monarchs, Ferdinand and Isabella, for his voyage to the New World).
“Whereby Columbus sailed with these unsought horses toward the New World.
“From these primitive Iberian south-meridional horses, that were none other than the wild form, that populated the banks of the rivers of the Peninsula, that were called Marismeños Españoles, were derived the American horses, because it was Marismeños, and no others, that were the horses brought by Colón (Columbus) on his second voyage.” --- Portugal Department of Agriculture: excepts from articles titled Español – Berber – Árabe, and Español Marismeño y Andaluz, published in the Annuals of the Criollo de Buenos Aires, and/or else where...
Great care had to be taken of the horses on the voyage. Yet that was not the worst of this trial by ocean travel. The end of the voyage could, by itself, eclipse all the mishaps and hazards of the months at sea. When it came to horses after a long ocean trip, the quivering, quavering, tremulous shock of landing was always the most critical consideration. That these temperate acclimated horses held on, without care or shelter, in the tropical conditions of Hispañola during the first days after disembarking, attests to their singular survival capacity. Nor was being cast upon foreign shores, with strange forage and fare, the whole of their troubles. There awaited the black clouds of Mayes or Chaquistíes, tiny bloodsucking insects, worse even than the Hispañola Island Mosquito (known today as The Hispañola National Bird).
The ship loads of horses that followed found well prepared quarters for the care of the new arrivals, yet being of less hardy blood, they never did fully get their feet under them, so to speak, and could not be used for the trip to the continent.
The Spanish Marismeño qualities were not diminished in the tropical
climates. In a few years,
the Spaniards were furnished with their best instrument for the occupation
of America. The campaigns
of Cortez in Mexico and Yucatan; those of DeSoto in Florida; those of Darien;
those of Pizarro in Peru;
Valdivia in Chile, Bolivia, and Argentina, all were the result of the
endurance, the rusticity, and the
acclimatization ability of these horses from the Peninsula.
During these incursions, the horses themselves, of course, were not to blame. The Spanish horse is easy to fool in one way – it trusts, loves, and is faithful to its user, needing no tether when trusted and loved in return. Since the day the first Spanish horse came into human hands, they have lent their keen senses and quick intelligence to enhance the reach and efficiency of the rider's undertakings.
The Spanish Conquistador leaders were accompanied by self reliant, fearless, and avid volunteers - wealthy hidalgos, and poor commoners - all who hoped to multiply their fortunes by plundering the new territories – all of who, through the course of their travels in the new world, learned deeply to cherish their unmatchable mounts.
Settlers followed the Conquistadors. There came farmers and ranchers; tradesmen and school teachers: cattle and hogs and chickens.
So it was that these Spanish horses of the most rustic kind were spread from the snows of the Andes to the tropical heat of Panama, Columbia, and Venezuela; from the altitudes of 19,680 feet in Ecuador and Peru; in the cold of Patagonia and the dirt of Fogo; in the frozen plains of North America and in the deserts of Arizona and Sonora. They lived always without anyone taking care of them, even in the canyons of Utah in places where human beings were barely able to go.
Everywhere that they ranged, and in every possible environment, the mares gave birth with such fertility, raising such foals that, from 300 mares brought to America at the beginning of the 16th century, within 100 years America was occupied by millions of horses.
