Claiborne also set records in the sales ring, first in 1973 with a Bold Ruler yearling which sold for $600,000 – a record at the time –and then in 1978 Claiborne consigned a little Northern Dancer colt from Special, she of a revered Claiborne family. The colt sold at Keeneland for $1.3 million, at the time the second-highest price ever for a yearling. Named Nureyev, he became a high-class racehorse abroad proved himself among the best sons of Northern Dancer in the breeding shed.

Seth Hancock reached a milestone for Claiborne Farm when Swale carried the Claiborne colors to victory in the 1984 Kentucky Derby. The homebred was from Tuerta, which had won the last stakes race his father, Bull Hancock, had seen won by a Claiborne horse.

The farm’s long-standing tradition of racing and breeding homebreds also paid off with two Breeders’ Cup winners, two-time Mile winner Lure, and Classic winner Blame. Raced in a partnership with Mrs. Adele Dilschneider, Blame, along with stakes winners such as Arch, Lea, and Elate, found success through this trusted friendship, a racing partnership that lasts to this day.

Hancock’s advice in the bloodstock enterprises of many of America’s industrial giants added to his influence. Claiborne attracted an impressive number of major businessmen to business. One of these clients was the illustrious Phipps family. Hancock became their bloodstock adviser, in addition to the other aspects of the relationship, and their partnership with Claiborne has endured to this day. Not only was Claiborne in the business to sell yearlings and board mares at the farm, but also attract investors to make possible the importation of desirable European bloodstock. The first notable stallion import was Sir Gallahad III in 1926. From his first American crop came the 1930 Triple Crown winner Gallant Fox.

Gallant Fox retired to Claiborne farm for his own stud duties, and in-turn sired the 1935 Triple Crown winner Omaha, the only father and son generational Triple Crown. The emerging Calumet Farm, was among investors who made possible Claiborne’s acquisition of Epsom Derby winner Blenheim II. Blenheim II also sired a Triple Crown winner in his first crop at Claiborne, the Calumet-bred Whirlaway in 1941. He was out of the mare Dustwhirl, who had been purchased from Claiborne. Claiborne was the leading breeder by earnings five times between 1935 and 1943. Arthur B. Hancock was the breeder of a record of 138 stakes winners, including 10 champions. Indeed, on his death in 1957, the English annual Bloodstock Breeders’ Review described Hancock as “probably the most influential breeder in the history of the American Turf.”