American Quarter

Horse

The American Quarter Horse is an American breed of horse that excels at sprinting short distances. Its name came from its ability to outdistance other breeds of horses in races of a quarter mile or less; some individuals 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 more than 5 million American Quarter Horses registered.

http://en.wikipedia.org/wiki/American_Quarter_Horse