or American Saddle Horse Breed of light horse that originated in the U.S. The breed was developed by crossing Thoroughbreds, Morgans, and Standardbreds on native mares having an easy gait. It stands 15-16 hands (5-5.3 ft [1.5-1.6 m]) high, and its colours are bay, brown, black, gray, and chestnut. Two show categories are for three-gaited and five-gaited horses. The three natural gaits are walk, trot, and canter; the five-gaited horse also has two trained gaits, the rack and the slow gait, or running walk. The American Saddlebred is also well known as a fine harness horse for show