Yes, it's true. There was anti-Catholic feeling in the USA, though very little of it remains today. My own experience is that CAF is a magnet attracting some who are virulently hostile to Protestantism.
As for the USA, 55 of the 56 who signed the Declaration of Independence were Protestants, and except for Kennedy, probably the most flagrant womanizer to ever occupy the White House, every president was a Protestant. Yet, millions of Catholics were welcomed to America. So, what was an overwhelming Protestant majority is now only about 2-1, Protestant to Catholic. That seems to speak reasonably well about the openness of Protestants to persons of others faiths over the years.
Protestant bigotry is bad, of course, as is Catholic or Orthodox bigotry. I know an Orthodox priest, a learned man and basically well-meaning, but he is not shy about indicating that his version of Christianity is the original and only valid one.
Frankly, we're all a bunch of sinners who should be careful of pride, whether about our religion or race or whatever. Then, again, I guess I do take pride in my country, though superpatriotism doesn't appeal to me. I always want my country to be better.
One experience. Years ago, when Franco was dictator of Spain, I visited that country. The fascist government there was in cahoots with the church and Protestants were not allowed to function openly. They had to worship underground. Franco, Mussolini and Hitler all were baptized Catholic, just as Lenin once thought of being an Orthodox priest. But that is irrelevant in 2009.
So, why do we waste time playing this game of one-upmanship? What Christians need to do is be less concerned about the superiority of one church over another and seek to work together, forgetting the past, as scripture advises, and going forward trusting in our one God and Redeemer. Protestants, Catholics and Orthodox all have soiled records, and we need to "let the dead bury the dead". As I recall, Jesus suggested that, too. It's when we try to justify horrendous sins of earlier times that we sound ridiculous. I need to resist that temptatuon myself, especially here in CAF where Protestantism seems to be a favorite whipping-boy and my impulse is to reply in kind.
May God forgive us all, and may He bless Catholics, Protestants, Orthodox and people of every creed, race, color, vocation, tongue and language. We must work to make religion a bridge and not a barrier.