Harold was an American

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 Thoroughbred

Thoroughbred

The Thoroughbred is a horse breed best known for its use in horse racing. Although the word thoroughbred is sometimes used to refer to any breed of purebred horse, it technically refers only to the Thoroughbred breed...

 racehorse

Horse racing

Horse racing is an equestrian sport that has a long history. Archaeological records indicate that horse racing occurred in ancient Babylon, Syria, and Egypt. Both chariot and mounted horse racing were events in the ancient Greek Olympics by 648 BC...

. He was bred by Aristides Welch

Aristides Welch

Aristides J. Welch was an American Thoroughbred racehorse breeder.Welch owned Erdenheim Stud at Chestnut Hill, Pennsylvania. In 1870 he purchased the mare Maggie B. B. from Captain T. G. Moore and stood her at Erdenheim. In 1872 he purchased the sire Leamington...

 who owned both his sire and his dam. Sired by Leamington

Leamington (horse)

Leamington was a Thoroughbred racehorse, and an influential sire in the United States during the second half of the nineteenth century. He was not only a fast horse, but also showed great staying ability....

, a four-time Leading sire in North America

Leading sire in North America

The list below shows the leading sire of Thoroughbred racehorses in North America for each year since 1830. This is determined by the amount of prizemoney won by the sire's progeny during the year...

, he was out of the great mare

Mare (horse)

A mare is an adult female horse or other equine.In most cases, a mare is a female horse over the age of three, and a filly is a female horse age three and younger. However, in Thoroughbred horse racing, a mare is defined as a female horse more than four years old; in harness racing a mare is a...

, Maggie B. B. who produced two other Classic winners: Iroquois

Iroquois (horse)

Iroquois , was the first American-bred Thoroughbred race horse to win the prestigious Epsom Derby at Epsom Downs Racecourse, Epsom, Surrey, England. He then went on to win the St...

, a full brother to Harold who became the first American-bred horse to ever win England's

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

 renowned Epsom Derby

Epsom Derby

The Derby Stakes, popularly known as The Derby, internationally as the Epsom Derby, and under its present sponsor as the Investec Derby, is a Group 1 flat horse race in Great Britain open to three-year-old thoroughbred colts and fillies...

, plus the colt Panique by Alarm who won the 1884 Belmont Stakes

Belmont Stakes

The Belmont Stakes is an American Grade I stakes Thoroughbred horse race held every June at Belmont Park in Elmont, New York. It is a 1.5-mile horse race, open to three year old Thoroughbreds. Colts and geldings carry a weight of 126 pounds ; fillies carry 121 pounds...

.

Harold was acquired by the prominent New York

New York

New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...

 stable owner, George L. Lorillard

George L. Lorillard

George Lyndes Lorillard was an American tobacco manufacturer and a prominent Thoroughbred racehorse owner.-Biography:He was born in Westchester, New York, the son of Pierre Lorillard III and Catherine Griswold. In 1760, his great-grandfather founded P. Lorillard and Company in New York City to...

. He entrusted his race conditioning to future U.S. racing Hall of Fame trainer R. W. Walden who would call Harold the best horse he had ever trained

Racing at age two, Harold won important races in 1878 and is regarded historically as the American Champion Two-Year-Old Male Horse. At age three, he won an American Classic, the Preakness Stakes

Preakness Stakes

The Preakness Stakes is an American flat Thoroughbred horse race for three-year-olds held on the third Saturday in May each year at Pimlico Race Course in Baltimore, Maryland. It is a Grade I race run over a distance of 9.5 furlongs on dirt. Colts and geldings carry 126 pounds ; fillies 121 lb...

, but in the ensuing Withers Stakes

Withers Stakes

The Withers Stakes is an American Thoroughbred horse race for three-year-olds willing to compete one mile on the dirt. Held at Aqueduct Racetrack every year at the end of April , it is a Grade III event, and offers a purse of $150,000...

 he suffered a ruptured blood vessel from which he never fully recovered and won only one more race before being retired to stud

Stud (animal)

A stud animal is a registered animal retained for breeding. The terms for the male of a given animal species usually imply that the animal is entire—that is, not castrated—and therefore capable of siring offspring...

. http://www.tbheritage.com/Portraits/MaggieBB.html

Harold died after serving just one full season at stud.