General Stud Book
Although named the Jersey Act by a critical foreign press, after Lord Jersey, the new regulation did not have the force of law as it was promulgated by the registration authorities of the Thoroughbred horse, not by the United Kingdom government. Nor was it promulgated by the Jockey Club, which had no authority over registration, only over racing matters. The regulation required that any horse registered in the "General Stud Book" trace in every line to a horse that had already been registered in the "General Stud Book", effectively excluding most American-bred Thoroughbreds.