Historians, including some of the good ones, have often proffered sweeping generalisations about American anti-Catholicism. You’ll read about it being “the deepest bias in the history of the American people” or the most “tenacious tradition of paranoiac agitation in American history”. The pity is that these analyses are not too far wide of the mark. It can sometimes become a little stereotypical, and we should not forget that plenty of Protestants in colonial or 19th-century America got along perfectly well with their Catholic neighbours. But the fundamental cultural animus against what they called “popery” back then is ludicrously easy to spot.