Britain and Brits had been there before and had been Catholic before it broke free from the power of the Roman empire, America was the first and only time that Catholicism was totally left out of the creation of a new nation, it bordered of course on a nation that had the more traditional Catholic background, Mexico.
You wrote:
“Britain and Brits had been there before and had been Catholic before it broke free from the power of the Roman empire,”
Incorrect. 1) ancient Britain never broke free of the Roman Empire. The Romans left - much to the regret of the Britains who wanted and needed their protection. 2) the Angles, Saxons and Jutes then invaded.
“America was the first and only time that Catholicism was totally left out of the creation of a new nation,”
False. Great Britain was created first and was Protestant.
“...it bordered of course on a nation that had the more traditional Catholic background, Mexico.”
And Canada. And there had already been Catholic settlers even in the 13 colonies.