General Stud Book
While still a three-year-old, he was exported to England where he was registered in the "General Stud Book". He was imported by Richard Croker, at a cost of about 8000 guineas. Americus' importation to England occurred before the imposition of the Jersey Act, which allowed him and his offspring to be registered in the "General Stud Book", something that would not have happened had he been imported into England after 1913, due to the Jersey Act's prohibition on registering horses tracing to Lexington in the "General Stud Book".