A bright chestnut grandson of Fair Play, Discovery was foaled at Mereworth Farm in Lexington, Kentucky. He was owned by Adolphe Pons of Country Life Farm in Bel Air, Maryland, who raced him at age two with limited success, winning only 2 of 13 starts and being beaten in several races by future Hall of Famer Cavalcade. Purchased for $25,000 by Alfred G. Vanderbilt II's Sagamore Farm, Discovery raced one more time in 1933, finishing second.
At age three, Discovery's racing season was marked by his continuing rivalry with Cavalcade. He finished 2nd to Cavalcade in the 1934 Kentucky Derby and 3rd to Cavalcade's 2nd in the Preakness Stakes. Both horses skipped the Belmont Stakes. Discovery went on to win the first of three consecutive Brooklyn and Whitney Handicaps (both under higher and higher weights), and set a world record time in the Rhode Island Handicap.
In 1935, Discovery was the dominant horse in the United States, and one of the most notable things about him was his ability to carry great weight. Running under an average of 131 pounds, the four-year-old won 11 of 19 races and was voted U.S. Champion Handicap and Horse of the Year honors. In the Merchants' and Citizens' Handicap, he carried 139 pounds. For these feats, he was called the great weight carrier, or the "Iron Horse."
The fact that Discovery was voted Horse of the Year in 1935 is an especially remarkable achievement because that was the same year in which Omaha won the Triple Crown. This was the only time that a Triple Crown horse failed to win Horse of the Year honors.
Racing at age 5, Discovery won his third Brooklyn and Whitney Handicaps en route to being voted his second straight U.S. Champion Handicap title.
Retired to stud at Vanderbilt's Sagamore Farm in rural Baltimore County, Maryland at the end of the 1936 racing season, over the course of a 21 year stallion career, Discovery sired just 25 graded stakes race winners. But it was through his daughters that Discovery left his legacy: they produced Hall of Fame Champions Native Dancer, Bold Ruler, and Bed o'Roses, as well as the multiple stakes winners Intentionally and Preakness Stakes winner Hasty Road. Native Dancer produced Raise a Native, who sired the stallion Mr. Prospector.
Discovery was inducted into the U.S. Racing Hall of Fame in 1969.