Leading broodmare sire in North America

The list below shows the leading Thoroughbred sire of broodmares in North America for each year since 1924. This is determined by the amount of prize money won during the year by racehorses which were foaled by a daughter of the sire. The most frequent sires on the list are Star Shoot (5), Princequillo (8), Mr. Prospector (9) and Sir Gallahad III (12).

...
Wikipedia