A quarter horse is a breed of horse known for its speed over short distances. The American Quarter Horse breed evolved during the early 1600s, as Arab, Turk, and Barb breeds were brought to America and crossed with horses from England and Ireland. The result was a compact, muscled horse that was ideal for short-distance racing. Characteristics include limited white markings on the face and below the knees, heavy muscling, and a gentle nature. There are 13 colors accepted by the American Quarter Horse Association (AQHA) as being indicative of quarter horse heritage - sorrel (most common), brown, chestnut, gray, dun, red dun, buckskin, black, bay, grullo, red roan, blue roan, and palamino. While the quarter horse is most widely known for its short-distance racing ability, it is also used to: 1)herd cattle, 2) numerous rodeo events and for 3) English classes of dressage and show jumping.

The bloodline of the American Quarter Horse has been preserved by the American Quarter Horse Association, which sets forth a strict set of guidelines in regard to registration. One of many such guidelines is the fact that each American Quarter Horse foal must have an American Quarter Horse sire (father) and an American Quarter Horse dam (mother). In order to keep accurate records of heritage, the AQHA maintains the largest equine registry in the world, with over 3.7 million registered American Quarter Horses. They keep track of all ownership records, performance and produce data, as well as American Quarter Horse population figures.

The American Quarter Horse Association's Worldwide Headquarters is located in Amarillo, Texas, and the American Quarter Horse Heritage Center and Museum is conventiently located right next door. The museum is open to the public and boasts a wide variety of research materials, exhibits, informative videos, and hands-on displays.

Some notable American Quarter Horses include King, who set the standard for American Quarter Horses; Go Man Go, who dominated the American Quarter Horse racing scene by setting three track records and one world record; Dash for Cash, considered one of the greatest sires of racing American Quarter Horses; and Easy Jet who, as a 2-year-old, had 22 wins from 26 starts.