Justin Morgan, 1792–1821, American horse, the foundation sire of the Justin Morgan breed of horses. Originally called "Figure," the stallion was renamed for his first owner, Justin Morgan (1747–97), after both owner and horse were dead. The horse—small, weighing about 800 lb (363 kg), of tremendous endurance, and with a delicate head, heavy shoulders, and a short neck—was bought and sold many times. The Morgan breed (see Morgan horse) preceded the Hambletonian strain as the favored type of trotting horses in America.

Morgan horse, breed of American light horse descended from a single progenitor—the famous Justin Morgan. Morgans are used as all-purpose light horses and are very popular on cattle ranches. Their average height is just under 15 hands (60 in./150 cm), and their average weight is about 1,000 lb (450 kg). Bay, chestnut, and black are common colors.