<Ul> <Li> Equus ferus caballus </Li> </Ul> <Li> Equus ferus caballus </Li> <P> The American Quarter Horse, or Quarter Horse, is an American breed of horse that excels at sprinting short distances . Its name came from its ability to outdistance other horse breeds in races of a quarter mile or less; some have been clocked at speeds up to 55 mph (88.5 km / h). The American Quarter Horse is the most popular breed in the United States today, and the American Quarter Horse Association is the largest breed registry in the world, with almost 3 million living American Quarter Horses registered in 2014 . </P> <P> The American Quarter Horse is well known both as a race horse and for its performance in rodeos, horse shows and as a working ranch horse . The compact body of the American Quarter Horse is well - suited to the intricate and speedy maneuvers required in reining, cutting, working cow horse, barrel racing, calf roping, and other western riding events, especially those involving live cattle . The American Quarter Horse is also shown in English disciplines, driving, and many other equestrian activities . </P>

Where did the name quarter horse come from