The Tennessee Walking Horse or Tennessee Walker is a breed of gaited horse known for its unique four-beat running-walk and flashy movement. It was originally developed as a riding horse on farms and plantations in the American South. It is a popular riding horse due to its calm disposition, smooth gaits and sure-footedness. The Tennessee Walking Horse is often seen in the show ring, but is also popular as a pleasure and trail riding horse using both English and Western equipment. Tennessee Walkers are also seen in movies, television, and other entertainment. The breed was developed beginning in the late 18th century when Narragansett Pacers and Canadian Pacers from the eastern United States were crossed with gaited Spanish Mustangs from Texas. Other breeds were later added, and in 1886 a foal named Black Allan was born. He is now considered the foundation sire of the breed. In 1935 the Tennessee Walking Horse Breeders' Association was formed, and it closed the studbook in 1947. In 1939, the first Tennessee Walking Horse National Celebration was held. In the early 21st century, this annual event attracted considerable attention and controversy because of issues linked to abuse of horses that was practiced to enhance their performance in the show ring. The two basic categories of Tennessee Walking Horse show competition are called "flat-shod" and "performance", distinguished by desired leg action. Flat-shod horses, wearing regular horseshoes, exhibit less exaggerated movement. Performance horses are shod with built-up pads or "stacks", along with other weighted action devices, creating the so-called "Big Lick" style. The United States Equestrian Federation and some breed organizations now prohibit the use of stacks and action devices at shows they sanction. In addition, the Tennessee Walking Horse is the breed most affected by the Horse Protection Act of 1970. It prohibits the practice of soring, abusive practices which can be used to enhance the Big Lick movement prized in the show ring. Despite the law, some horses are still being abused. The controversy over continuing soring practices has led to a split within the breed community, criminal charges against a number of individuals, and the creation of separate breed organizations. Congressional legislation to strengthen the Act has been introduced with broad support, but has yet to be enacted. Breed characteristics The modern Tennessee Walking Horse is described as "refined and elegant, yet solidly built". It is a tall horse with a long neck.