Despite Faith's fantastic assertions that there is any attempt to get rid of Christianity in the US the reality is that even before there were States the country and its citizenry were increasingly secular. Even in strongly Methodist and Baptist Virginia most folk just didn't go to church. Sunday horse races took precedence over Sunday Church most everywhere.
What folk were aware of though was the threat that was the various Christian denominations. Several of the Colonies had been created specifically as refuges from other Christian sects and if they were to ever become States, part of a Union, then there needed to be some method that assured no sect could ever gain political power.
The result in Religious Colony after Religious Colony with the exception New England was the establishment of conditions in their constitutions requiring religious freedom. Not all the colonies were established based on religion.
The first British Colony was Virginia and it was a commercial secular venture, not religious. Georgia was also a secular venture and not religious. New York, Delaware, New Jersey, New Hampshire, Delaware, North and South Carolina were also all initially commercial endeavors. So at least nine of the original thirteen colonies were secular commercial creations as opposed to religious.
Anyone so limited that they can only spell a word one way is severely handicapped!