Yes, indeed, Brits and a few Dutch who arrived with them. But ‘American’ or even ‘America’ isn’t the operative word here. It was used simply to demonstrate how far off the beaten path (the western hemisphere, in the 17th century, for goodness’ sake) Calvinists had strayed in pursuit of what they believed Calvin taught (part of which was sola scriptura), answerable to no higher authority than their own obviously faulty understanding of the scriptures.
Protestants did create the greatest nation that man has ever created though, so when you point out imperfections like a British town hanging a few witches before the United States even existed, you don’t need to smear America.