Yes they are. And the fact is there were more than a few Catholics in America from the beginning.....and that’s not even counting Florida and Louisiana which were settled before 1700 in the latter case and before 1600 in the former case.
You seem to be making up some fake number in your head that the historians and records have all missed, what imaginary number or percentage is in your head?
Florida and Louisiana were not part of America before the 1800s anyway, they were not part of us as our British colonies and not part of our United States at our founding.
Around 120 years after your 1700 date, Florida became part of America, and in the 1830 census Florida had just under 35,000 white people total.
In Louisiana 103 years after your 1700 date, it became part of America and in the 1810 census had 34,000 white people.