Where this discussion generally breaks down is in the definition of 'Christian Nation.' Generally those who oppose the term will state that America is not officially Christian, and will point to the Treaty of Tripoli or to the Establishment Clause, to which opponents will retort that America was founded on so-called 'Christian Values,' and that makes it a Christian nation. This much at least is hard to deny, many of the earliest settlers were very devout Christians (the puritans especially) and at least some of their beliefs are still important today (the so-called 'Protestant Work Ethic' being the most famous). Additionally, every US President has been (at least nominally) Christian, along with the vast majority of legislators in Congress, going all the way back to 1789. This is generally reflective of population, as a significant majority of Americans have identified as Christian for the entire life of the Republic.

Overall, its hard to deny the influence of Christianity and Christian thought over colonial and revolutionary America, but its also important to point out that the founders took steps to demonstrate that Christianity was not the only faith that could be practiced in the new country.

• The Constitution states clearly that the authority of the government rests with the people, rather than an appeal to any higher power. While it is often claimed that the Constitution claims no reference to God, this is not entirely accurate, the date in article 7 is referred to this way:

done in Convention by the Unanimous Consent of the States present the Seventeenth Day of September in the Year of our Lord one thousand seven hundred and Eighty seven

However, this is not any more of an endorsement than using A.D. would be today.

• Natural Rights: At the debate over the Bill of Rights, Theodore Sedgwick sarcastically wondered why not include 'a man should have a right to wear his hat if he pleased; that he might get up when he pleased, and go to bed when he thought proper?' While he was being facetious, his observation gets at an underlying principal of the Bill of Rights, that it is not supposed to grant rights, merely reflect a few of the rights that every free person should possess automatically. This is made clear by the 9th Amendment which stipulates 'The enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people.' i.e. just because we didn't write it down, doesn't mean that you don't have it as a right. Going by this logical framework, the First Amendment is not establishing merely that Congress isn't allowed to limit free expression of religion, but that 'free exercise' of Religion is a basic and fundamental natural right of all free peoples.

Sources:

• Federalist 84 Hamilton argues against those claiming that the Bill of Rights is not necessary. Although he does note that the rights have their basis in English Common Law.

• Letter from Jefferson to Madison 1789 Jefferson expresses his view of why abill of rights is important, though stating that it would be 'A positive declaration of some essential rights.' Rather than the source of said rights.

• Leviathan by Thomas Hobbes - Influential on the Founders, makes the distinction between Civil and Natural laws. Civil laws being those created by organizations, while Natural Laws are general rules discovered by reason.

• Alexander Hamilton by Ron Chernow

• Madison, a life Reconsidered by Lynn Cheney

• Ben Franklin, an American Life Not the most relevant, but Franklin was an advocate for Natural Rights and Natural Law.

Because it was. First, you have the Puritans coming over on the Mayflower. You also had the Catholics coming over on the Ark & Dove. The English colonists that first colonized what is today the United States did so to get away from the Church of England. Under the Church of England, other religions were considered "hostile". For instance, the Penal Laws were enforced against Catholics, causing as many as a few thousand people in England alone to die for their beliefs between the 16th and most of the 17th Centuries. To get away from the Penal laws, many adherents to religions that weren't the Church of England fled to New World. It's because of this that we have the first amendment. "Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof" When they are talking about religion, they don't mean the overall umbrellas of the various philosophical adherents but the specific sects.