Bred by Paul Mellon and raced under his Rokeby Stable colors, Key to the Mint was trained by future Hall of Fame inductee Elliott Burch.
Key to the Mint did not run in the Kentucky Derby, the first race of the U.S.
Following the Triple Crown races, Key to the Mint dominated his age group in 1972 and was voted the Eclipse Award for American Champion Three-Year-Old Male Horse.
He continued to race at age four, notably winning the 1973 Excelsior Handicap and won on a sloppy track for 10 furlongs in winning the Suburban Handicap.
Retired to stud duty, Key to the Mint sired Plugged Nickle, the 1980 American Champion Sprint Horse; Java Gold, a multiple Grade 1 winner and sire of Kona Gold; and Jewel Princess, the 1996 American Champion Older Female Horse.