The U.S. government was created with the mandate to not establish any state religion or to forbid any religion. There were a couple of ways this could have gone.
Here’s one path that was not taken. The freedom of religion and the separation of religion from the state could have encouraged a widespread understanding of what a crock of malarkey religion all is. If no religion can actually persuade everyone of its claims, if people choose their various and sundry religions based on factors wholly