We went from imperial rule to a Catholic State

Faced, as he once was, with the same difficulties that existed here, Thomas Jefferson, and the founding fathers of the US, also saw the need to keep religion out of the affairs of state, and acted accordingly, separating church and state in the constitution.
The soil of Europe, he proclaimed, had, for centuries, been soaked in blood, caused by religious conflict amongst Christians, and he didn’t want that to happen in the US.