The term Thoroughbred describes a breed of horse whose ancestry traces back to three foundation sires - the Darley Arabian, the Godolphin Arabian and the Byerly Turk. Named after their respective owners - Thomas Darley, Lord Godolphin and Captain Robert Byerly - these three stallions were brought to England from the Mediterranean Middle East around the turn of the 17th century and bred to the stronger, but less precocious, native horse. The result was an animal that could carry weight with sustained speed over extended distances, qualities which brought a new dimension to the burgeoning, aristocratically supported, sport of horse racing.

So began a selective breeding process which has been going on for more than 300 years, breeding the best stallions to the best mares, with the proof of superiority and excellence being established on the race track. Key to this selective breeding process is the integrity of the breed's records. In early days, Thoroughbred breeding records were sparse and frequently incomplete, it being the custom, among other things, not to name a horse until it had proved outstanding ability. It was left to James Weatherby, through his own research and by consolidation of a number of privately kept pedigree records, to publish the first volume of the General Stud Book.

He did this in 1791, listing the pedigrees of 387 mares, each of which could be traced back to Eclipse, a direct descendent of the Darley Arabian; Matchem, a grandson of the Godolphin Arabian; and Herod, whose great-great grandsire was the Byerly Turk. The General Stud Book is still published in England by Weatherby and Sons, Secretaries to the English Jockey Club.

Several years later, as racing proliferated in the fast-expanding continent of North America, the need for a pedigree registry of American-bred Thoroughbreds, similar to the General Stud Book, became apparent. Col. Sanders D. Bruce, a Kentuckian who had spent almost a lifetime researching the pedigrees of American Thoroughbreds, published the first volume of The American StudBook in 1873. Bruce closely followed the pattern of the first General Stud Book, producing six volumes of the register until 1896, when the project was taken over by The Jockey Club.

When The Jockey Club published its first volume of the studbook the foal crop was about 3,000. By 1986 it exceeded 51,000. The Jockey Club embraced new computer technology to meet the registration challenges posed by such large numbers. Today, The Jockey Club manages one of the most sophisticated computer operations in the country. Its database holds the names of more than 3 million horses on a master pedigree file, names that trace back to the late 1800's. The system also handles daily results of every Thoroughbred race in North America, as well as processing electronically transmitted pedigree and racing data from England, Ireland, France, Australia, Japan and other leading Thoroughbred racing countries around the world.

What began as a pastime and sporting amusement for the wealthy has now become a worldwide multi-million dollar industry whose economic impact is widely felt at regional and national levels. From license fees and direct taxes on pari-mutuel handle Thoroughbred racing generates nearly $500 million in government revenue each year. But this is relatively minor in comparison to the overall urban and rural economic contribution made by the wide and varied infrastructure of the racing and breeding industry as a whole. A recent estimate, for example, put the industry's contribution to the economy of New York State alone at more than $1.8 billion each year.

The Thoroughbred is one of the most brilliant and versatile horses bred in the world today. Noted for its ability to carry speed over extended distances, the Thoroughbred is also a popular choice among horsemen in many disciplines beyond the race track, including hunting, jumping, eventing and polo. The Thoroughbred has been used to create new breeds of horses and to upgrade others. The key to the Thoroughbred's greatness is its speed and endurance, for which it has been bred for over 300 years.


The Thoroughbred stands a little over 16 hands on average and its appearance reveals its Arabian ancestry. A refined head with widely-spaced, intelligent eyes sits on a neck which is somewhat longer and lighter than in other breeds. The withers are high and well defined, leading to an evenly curved back. The shoulder is deep, well-muscled and extremely sloped while the heart girth is deep and relatively narrow. The legs are clean and long with pronounced tendons and move smoothly in unison through one plane. The bone structure of the upper hind leg makes room for long, strong muscling. The thighbone is long and the angle it makes with the hipbone is wide. The powerful muscling of the hip and thigh continues to the gaskin that is set low. Coat colors in Thoroughbreds may be bay, dark bay, chestnut, black or gray; roans are seen only rarely. White markings are frequently seen on both the face and legs.