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.

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.

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.
Anaqua
Annahi
Arch Oldham
Ashwell
Baby Steel
Band Play
Band Time
Bar Admiral
Barbara Lam
Barre Granite
Barrera
Bayard
Bayard II
Be Sure Now
Beadsman
Begger Boy
Big Klu
Big Red Bar
Bimelech
Blob
Blue Chord
Blue Gray
Bold Venture
Boojum
Boyarsky
Brettenham
Buggins
Bull Boy
Buster Brown
Bymeabond
Cambridgeshire
Candyman Bee
Candy Mark
Captains Courageous
Cattail
Chain Lay
Cherry Lake*
Chicaro
Chicle
Chimney Sweep
Close Watch
Coldstream
Confidant
Crafty Actor
Credit Balance
Dark Quarry
Deep Note
Deep Sun
Dennis Reed
Dewey
Doc Horn
Dolly Dimples
Domino
Donie Dune
Dorothy E
Dothan
Double Feature
Dr Mack
Drayab
Eskrine Dale
Esters Little Klu*
Everett
Glass Bar
Good Bird
Green Flash
Greenock
Grey Leg
Fame We Will
Fast Fellow
Feast
Find A Buyer
Fire Dog
First Ambassador
Fix-n-Mix
Fleet Kirsch
Fleeting Time
Flying Squirrel
Forever Young
Hadif
Handy Shot
Hawkins Special
Hijo Beauty
Hoist Bar
Horace H
Hy Aethel
Hy Diamond
Hygro
Hysition
I’ll Go
Jacks Jet
Jackstraw Jr
Jerry Crow
Jetalong
Joe Blair
Johnny X
Kicapu Kid
Killoqua
King O’Neill
King Plaudit
Lady Albert G
Lady Johnnie
Lady Woodchuck
Lake Erie
Lani Chief
Lanolark
Lantana Belle
Lawyer
Leannie
Lilsalady
Line Up
Lite the Fuse
Little Request
Little Vic
Lnatural
Long Chance
Los Molinos
Lost Cause
Lucky Bar
Lucky Mose
Luke McLuke
Mad Way
Madder Music
Magical Mile
Major Speck
Mary Greenock
Master Bunting
Master Gould
Maynard L
Mayshego
Midway
Miss Bank
Miss Pines
Moolah Bux
Mr Good
Murrtheblurr
Nassak
Native Orphan
Nativo
No Cat
Noholme
Noo Music
Now Is The Time
Official
Oil Rig
Olympic Win
Orto Mambo
Osage Streaker
Pass Em Up
Past Due
Patriotic
Peace Pipe
Pleasure Fund
Polamandy
Pondariel
Porte Drapeau
Prince Vic
Provocation
Pukka Gent
R Smith
Raffles
Rancocas
Real Dish
Really Rugged
Reb’s Policy
Red Jewel
Rejected
Rene Depot
Reno Lord
Restless Runner
Rhonda K
Riches and Honor
Roulade
Royal Bob
Royal Charger
Rulla Bux
Salutation
Sculptor’s Whim
Seabiscuit
Sheridan
Shirleys Champion
Slewacide
Smash It
Spanish Way
Spot Cash
Spy Song
Star Shoot
Texas Dancer
Thermos
Tilt The Odds
Trippy Dip*
Truly Truckle
Truxton King
Uncle Jimmy Gray
Universe
Venetian Jester
Very Wise
Vikingson
War Bam
Wave of Erie
Wayward Irving
Westy Rambler
What’s Cookin
With Regards
Yankee Doll