Thoroughbred horses played an integral role in the development of other breeds. Their conformation, speed, and agility contributed to the talent of modern performance horses. Today, the names of Thoroughbred stallions and mares can be found stamped in the pedigrees of proven racing, barrel racing, cutting, reining, roping, pleasure, and halter horses.

Piggin String, a Thoroughbred stallion foaled in 1942, won short distance races and performance horse classes. He was said to be the ideal Quarter Horse.

The Thoroughbred is the result of a selective breeding program that began at the turn of the 17th century. Stallions imported from the Mediterranean Middle East were crossed with strong English mares. Their excellence was tested on the race track and became a popular sporting event in Europe. As horse racing spread into North America, colonists sought to make the sport their own. Thrilling quarter-mile races were held as early as 1674 in Virginia. To meet the demand of these short races, some breeding programs shifted to produce a type of Thoroughbred that was suitable for sprinting. Like the sprinters of today, they were muscular, compact, and athletic.

The phrase ‘Celebrated American Quarter Running Horse’ denoted top sprinters in early Thoroughbred stud books. The phrase was later shortened and became the designation of a new breed in 1940 when the American Quarter Horse Association was founded. The first twenty foundation sires registered with the AQHA are all descended from Thoroughbreds. Actulally of the first twenty, Rialto, Chief, Colonel, Sheik, Whiskaway, and Little Richard have Thoroughbred grandparents, and Joe Reed and Oklahoma Star have Thoroughbred parents.

Little Lena Bars, a Thoroughbred mare foaled in 1960, set numerous track and world records against Quarter Horses. She was a full sister to Lena’s Bar, the dam of Easy Jet.

Even after the new breed was established, Thoroughbreds such as Piggin String, Woven Web, and Brigand continued to set track records and earn Champion Quarter Running Horse titles. Then in the 1960s, Little Lena Bars equaled the world record at 220 yards, and set new world records at 250, 300, and 330 yards. She also equaled and set new track records at 400 and 440 yards. Her dominance prompted retaliation from the young AQHA. When the organization realized that nearly all the records in Quarter Horse racing belonged to a Thoroughbred, they deleted all mention of times and records set by Thoroughbreds and banned the breed from major Quarter Horse races.

Despite this pushback, Thoroughbreds remained vital to the Quarter Horse industry. Old-school horseman will tell you that the best qualities of running horses come directly from Thoroughbreds. This is could be the reason why they are just as influential today as they were in the 1940s. We have compiled a list of Thoroughbreds that were important in the development and improvement of modern performance horses. Click on a horse’s name to read more about them. An asterisk denotes a horse that has been inducted into the AQHA Hall of Fame.

A Fore Thought

Afton Creek

Anchor Watch


Azure Te*

Bar Admiral
Bayard II


Begger Boy
Big Red Bar
Blue Chord
Blue Gray


Buster Brown
Captains Courageous
Chain Lay
Cherry Lake*
Close Watch

Coup De Kas

Custus Rastus 

Dark Quarry

Depth Charge* 

Direct Win

Disco Jerry 

Dolly Dimples
Donie Dune
Glass Bar
Good Bird
Grey Leg
Fame We Will

Favorite Trick 

Find A Buyer

Fol’s Native

Forever Young
Hawkins Special


Hy Diamond


Jackstraw Jr

Jim J. 

Johnny X
Lake Erie
Lani Chief

Lena’s Bar*

Little Lena Bars

Little Request
Little Vic
Los Molinas
Lucky Bar
Major Speck


Master Bunting

Master Hand 

Maynard L

Mito Paint 

No Cat
Noo Music
Pass Em Up

Piggin String 


Raise Your Glass 

Real Dish
Rene Depot
Rhonda K
Riches and Honor

Rocket Bar*

Royal Bob

Salt Lake

Spanish Way

Spotted Bull

Spy Song

Staunch Avenger

Storm Cat 

Swift Solo 

Three Bars* 

Top Deck*

Trippy Dip*
Truly Truckle
Uncle Jimmy Gray


Westy Rambler
What’s Cookin

Woven Web*