Anti-Catholic speech and activity goes back five hundred years. You'd be surprised to find that many of the arguments you hear today were originally formed during the political and social upheaval that coincided with the Reformation. As the Colonists were primarily English and Dutch, these two nations' mindsets and prejudices were strongly reflected in American culture for the first 150 years of its existence.
As German, Italian, Polish and Irish immigrants crossed the Atlantic, they brought their Catholic communities and theology with them. The ritual nature of Catholic liturgy, its being said in Latin, and the hierarchy of clergy all clashed deeply with American religious sensitivity as it was going through the throes of the Restoration movement. While the Colonists were often Anglican or Presbyterian, newer "Bible-believing" groups were springing up, particularly as farmers and pioneers settled the South and West. It was difficult in that Catholic customs seemed alien in and of themselves, but combine this with a history of anti-Catholic propaganda, and the backlash was stunning.
Consider that the Knights of Columbus developed not as the middle-aged guys' selling tootsie rolls to raise money for people with developmental disabilities, but rather as a social movement to protest anti-Catholic discrimination. There was a time when many jurisdictions forbade Catholics from holding jobs, or going to school, or simply refused to prosecute those who prevented Catholics from engaging in society. The growth of the Catholic school system is due in part to the response to this discrimination.
One would hope that in these more enlightened times when access to information is free and easy, there would be no more of this rhetoric. Yet the misunderstandings continue, and not just on these boards. A friend who I have known for 10 years, and a Presbyterian seminarian, kept a candle of the Virgin Mary in his bathroom. I commented on it, and asked if he held a devotion, but he said "She's seen all those penises, and is still a virgin!" He later apologized when I replaced his candle with a devotional to the Sacred Heart of Jesus. Note that this is a college-educated graduate student, and we were actually roommates for two years. I must say, I am heartened that he no longer wants to work to convert Catholics to another faith, but wants to work to support Catholics in living the Catholic faith to know Christ better. I think after all of our late-night conversations, he sees where he was overemphasizing some things (Mary, the Saints, the Deuterocanonicals), and finally realized that the point of the Catholic Church is that of any Church : to bring the believer to Christ.
Anyway, the work remains to be done. If you have the energy for it, we welcome all who wish to dispel ignorance. I have no qualms with someone who dislikes the Catholic Church for what she preaches, so long as he or she understands what it actually does preach. This requires much research, much prayer and a lot of patience.