From the OP:
Was America founded on or meant to be Christian? ...Do you agree that Christianity was the moral grounding for our nation or was it something else? Is thete any evidence to support your idea?
The flagship instrument that evinces the answer to your question is USA's "We the people..." contract aka "the constitution."
And that instrument is void of any mention of God.
"God" to its forerunning document-writers may have been a Deist God or a Great Spirit as well as the Christian God
God calls that
idolatry.
The persona/status of its signatories, or the personal beliefs of its crafters, is without standing in law. Bottom line: The contract is, what it is -- a contract void of any mention of God.
'Save us!', they cried to Caesar. "The constitution" offers a worldly protection racket based in vain deceit; civil idolatry. Do you feel more protected now with its gov't jack-booted thugs banging down your castle door?
All of the laws of the natural man are for their own, for their "things." This is how the 'police power' attaches to those who do not sojourn in Christ. Those dead to Christ are made after the image that created them. For example, under man's law, 'the State' is a corporation, and a corporation has no soul. Therefore, it's a dead thing, and they are dead to Christ, and they are made in the image of Caesar, because they live by all the corporate laws that Caesar creates. Corporations, or the corporate governments, always mark their property, or 'things', with 'legal descriptions' -- e.g. the ALL CAPS legal fictions for its citizens, as previously documented
here.
Buyer beware.