Rosemont was an American 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...

 best known for his win in the 1937 Santa Anita Handicap

Santa Anita Handicap

The Santa Anita Handicap is an American Thoroughbred horse race held annually in early March at Santa Anita Park in Arcadia, California. It is a Grade I race for horses four years old and up , and is considered the most important race for older horses in North America during the winter racing season...

, defeating Seabiscuit

Seabiscuit

Seabiscuit was a champion Thoroughbred racehorse in the United States. From an inauspicious start, Seabiscuit became an unlikely champion and a symbol of hope to many Americans during the Great Depression...

, a scene used in the 2003 motion picture Seabiscuit

Seabiscuit (film)

Seabiscuit is a 2003 American biographical film based on the best-selling non-fiction book Seabiscuit: An American Legend by Laura Hillenbrand...

. http://pqasb.pqarchiver.com/latimes/access/394957051.html?dids=394957051:394957051&FMT=ABS&FMTS=ABS:AI&type=historic&date=Feb+28%2C+1937&author=&pub=Los+Angeles+Times&desc=MIGHTY+ROSEMONT+NOSES+OUT+SEABISCUIT+TO+WIN+%24100%2C000+HANDICAP+IN+SMASHING+DRIVE+DOWN+HOME+STRETCH&pqatl=google

Listed as being bred by William duPont, Jr.

William duPont, Jr.

William duPont, Jr. was an American businessman and banker and a prominent figure in the sport of thoroughbred horse racing. A member of the Delaware Du Pont family, he was the son of William du Pont and Annie Rogers , and brother to horsewoman, Marion.In 1919, he married Jean Liseter Austin...

, Rosemont was actually purchased at a dispersal sale when his dam was still in foal. He was raced under du'Pont's Foxcatcher Farm banner and trainer by Richard E. Handlen

Richard E. Handlen

Richard E. "Dick" Handlen was an American Thoroughbred horse racing trainer whom the March 15, 1937 edition of the Los Angeles Times called "one of the best trainers in America"...

. Among his other wins, Rosemont defeated Triple Crown

United States Triple Crown of Thoroughbred Racing

In the United States, the "Triple Crown" is usually the Triple Crown of Thoroughbred Racing, a series of three Thoroughbred horse races for three-year-old horses run in May and early June of each year consisting of the Kentucky Derby, Preakness Stakes, and Belmont Stakes.While Daily Racing Form...

 winner Omaha

Omaha (horse)

Omaha was a United States thoroughbred horse racing champion.Foaled at Claiborne Farm in Paris, Kentucky, he was the son of 1930 U.S. Triple Crown winner Gallant Fox and the mare Flambino. Omaha was the third horse to win the Triple Crown having won as a three-year-old in 1935.Omaha was an...

 in winning the 1935 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...

. http://select.nytimes.com/gst/abstract.html?res=F1081EF63B59107A93C4AB178ED85F418385F9

Following his retirement from racing, Rosemont stood at 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...

 at William duPont's Walnut Hall Farm near Boyce, Virginia

Boyce, Virginia

Boyce is a town in Clarke County, Virginia, United States. The population was 426 at the 2000 census.-Geography:Boyce is located at ....

 where he was foaled in 1932. Of his progeny, Rosemont is best known as the sire of U.S. Racing Hall of Fame

National Museum of Racing and Hall of Fame

The National Museum of Racing and Hall of Fame was founded in 1950 in Saratoga Springs, New York, to honor the achievements of American thoroughbred race horses, jockeys, and trainers...

 inductee, Bed O' Roses and as the damsire of Berlo

Berlo

Berlo was an American Thoroughbred Champion racehorse. Bred by William duPont, Jr. at his Walnut Hall Farm near Boyce, Virginia, she was out of the mare Faberose, a daughter of duPont's Santa Anita Handicap winner, Rosemont...

, the 1960 American Champion Three-Year-Old Filly.