"The kind of anti-Catholic hysteria of then is pretty similar to the anti-Muslim hysteria of today. I'm not saying that caution is unwarranted with some Muslims--it IS. But it's important to note that accusations that a group (now "Muslims") is more tied to their religion than our country is not a new complaint."
They expected the Pope to take over the Western US. Lyman Beecher wrote that he went to Cincinnati from Boston "to battle the Pope for the garden spot of the world."
To give you some perspective, well more than 80% of our country lies to the west of Cincinnati, and the Vatican DID have a history of conquest way back when. So...the similarities are there.