Notably, there are about 82,000 feral horses that roam freely in the wild in certain parts of the country, mostly in the Western United States. While genus Equus, of which the horse is a member, originally evolved in North America, the horse became extinct on the continent approximately 8,000–12,000 years ago.
In 1493, on Christopher Columbus' second voyage to the Americas, Spanish horses, representing E. Catullus, were brought back to North America, first to the Virgin Islands ; they were reintroduced to the continental mainland by Hernán Cortés in 1519. From early Spanish imports to Mexico and Florida, horses moved north, supplemented by later imports to the east and west coasts brought by British, French, and other European colonists.
Native peoples of the Americas quickly obtained horses and developed their own horse culture that was largely distinct from European traditions. Horses remained an integral part of American rural and urban life until the 20th century, when the widespread emergence of mechanization caused their use for industrial, economic, and transportation purposes to decline.
Modern use of the horse in the United States is primarily for recreation and entertainment, though some horses are still used for specialized tasks. A 2005 genetic study of fossils found evidence for three genetically divergent equip lineages in Pleistocene North and South America.
Recent studies suggest all North American fossils of caballine-type horses, including both the domesticated horse and Przewalski's horse, belong to the same species: E. ferns. Remains attributed to a variety of species and lumped as New World stilt-legged horses belong to a second species that was endemic to North America, now called Haringtonhippus Francisco.
Digs in western Canada have unearthed clear evidence horses existed in North America as recently as 12,000 years ago. Other studies produced evidence that horses in the Americas existed until 8,000–10,000 years ago.
Equine in North America ultimately became extinct, along with most of the other New World megafauna during the Quaternary extinction event during the Pleistocene-Holocene transition between 15,000 and 10,000 years ago. Given the suddenness of the event and because these mammals had been flourishing for millions of years previously, something unusual must have happened.
The first main hypothesis attributes extinction to climate change. For example, in Alaska, beginning approximately 12,500 years ago, the grasses characteristic of a steppe ecosystem gave way to shrub tundra, which was covered with unpalatable plants.
However, it has also been proposed that the steppe-tundra vegetation transition in Bering may have been a consequence, rather than a cause, of the extinction of megafaunal grazers. The other hypothesis suggests extinction was linked to overexploitation of native prey by newly arrived humans.
The extinctions were roughly simultaneous with the end of the most recent glacial advance and the appearance of the big game-hunting Clovis culture. Several studies have indicated humans probably arrived in Alaska at the same time or shortly before the local extinction of horses.
Horses returned to the Americas thousands of years later, well after domestication of the horse, beginning with Christopher Columbus in 1493. These were Iberian horses first brought to Hispaniola and later to Panama, Mexico, Brazil, Peru, Argentina, and, in 1538, Florida.
The first horses to return to the main continent were 16 specifically identified horses brought by Hernán Cortés in 1519. Subsequent explorers, such as Coronado and De Soto brought ever-larger numbers, some from Spain and others from breeding establishments set up by the Spanish in the Caribbean.
The first imports were smaller animals suited to the size restrictions imposed by ships. Starting in the mid-19th century, larger draft horses began to be imported, and by the 1880s, thousands had arrived.
Formal horse racing in the United States dates back to 1665, when a racecourse was opened on the Hempstead Plains near Salisbury in what is now Nassau County, New York. There are multiple theories for how Native American people obtained horses from the Spanish, but early capture of stray horses during the 16th century was unlikely due to the need to simultaneously acquire the skills to ride and manage them.
It is unlikely that Native people obtained horses in significant numbers to become a horse culture any earlier than 1630–1650. From a trade center in the Santa Fe, New Mexico area, the horse spread slowly north.
The Comanche people were thought to be among the first tribes to obtain horses and use them successfully. By 1742, there were reports by white explorers that the Crow and Blackfoot people had horses, and probably had them for a considerable time.
The horse became an integral part of the lives and culture of Native Americans, especially the Plains Indians, who viewed them as a source of wealth and used them for hunting, travel, and warfare. In the west, they were ridden by cowboys for handling cattle on the large ranches of the region and on cattle drives.
In some cases, their labor was deemed more efficient than using steam-powered equipment to power certain types of mechanized equipment. At the same time, the maltreatment of horses in cities such as New York, where over 130,000 horses were used, led to the creation of the first ASPCA in 1866.
In the 19th century, the Standard bred breed of harness racing horse developed in the United States, and many thoroughbred horse races were established. Horse-drawn sightseeing bus, 1942At the start of the 20th century, the United States Department of Agriculture began to establish breeding farms for research, to preserve American horse breeds, and to develop horses for military and agricultural purposes.
However, after the end of World War I, the increased use of mechanized transportation resulted in a decline in the horse populations, with a 1926 report noting horse prices were the lowest they had been in 60 years. In 1912, the United States and Russia held the most horses in the world, with the U.S. having the second-highest number.
There were an estimated 20 million horses in March 1915 in the United States. But as increased mechanization reduced the need for horses as working animals, populations declined.
A USDA census in 1959 showed the horse population had dropped to 4.5 million. Numbers began to rebound somewhat, and by 1968 there were about 7 million horses, mostly used for riding.
^ One hypothesis posits that horses survived the ice age in North America, but no physical evidence has been found to substantiate this claim. United States Equestrian Federation.
“Ascent and decline of monodactyl equips: a case for prehistoric overkill” (PDF). “Evolution, systematic, and paleogeography of Pleistocene horses in the New World: a molecular perspective”.
“Ancient DNA Clarifies the Evolutionary History of American Late Pleistocene Equips”. ^ Hartman, Peter D; Paula, Grant D; Machete, Ross DE; Scott, Eric; Cahill, James A; Choose, Brianna K; Knapp, Joshua D; Stiller, Mathias; Woollier, Matthew J; Orlando, Ludovic; South on, John (November 28, 2017).
“Rapid body size decline in Alaskan Pleistocene horses before extinction”. “Steppe-tundra transition: a herbivore-driven biome shift at the end of the Pleistocene”.
“A calendar chronology for Pleistocene mammoth and horse extinction in North America based on Bayesian radiocarbon calibration”. ^ Slow, Andrew; Roberts, David; Robert, Karen (May 9, 2006).
“On the Pleistocene extinctions of Alaskan mammoths and horses ". Proceedings of the National Academy of Sciences of the United States of America (19 ed.).
“New carbon dates link climatic change with human colonization and Pleistocene extinctions”. “Iberian Origins of New World Horse Breeds”.
Report of the Chief of the Bureau of Animal Industry, United States Department of Agriculture. Horses in Society: A Story of Animal Breeding and Marketing, 1800–1920.