Many false legends targeted the Church. Taken as conventional wisdom by most and part of our cultural DNA (even for Catholics) yet serious historians know them to be false. Many of these legends come out of post reformation England to lure souls to the Church of England. Because the tales are so old, they are taken as historical fact when in fact they were canards to begin with.
Consider also that American has inherited much of its history from the English and at the time of early America, England had a bitter hatred for the French and Spanish (both Catholic countries).