Ed Brayton points me to this summation by Jonothan Rowe of the position that America the nation was not founded as a "Christian nation" as understood by many evangelicals. Rowe links to this article in a Christian magazine which makes that case Thomas Jefferson was not an "orthodox" Christian as conservative Protestants would understand the term. I am not an expert in this area, but I have read enough of Jefferson's correspondence and biographies to be skeptical that the man would have affirmed the Nicene Creed, which seems a necessary condition for claiming him as an orthodox Christian, but I have seen fundamentalists assert exactly this. Of course, there is a flip side, I have met atheists who deny that Constantine was genuinely a Christian, after all, he sanctioned the depiction of Sol Invictus on coins after his reputed conversion and held pagan priestly offices. The argument is that Constantine was an opportunist who never believed in Christianity, and the faith's rise was simply a Machiavellian ploy. But the sum totality of the historical record would seem to suggest that Constantine did believe himself to be a Christian, and would be recognized as such by Christians today (with allowances made for the fact that the Nicene Creed was obviously not formulated until near the end of his life and that deathbed baptism was not uncommon during this period).

The point is that the furthering of knowledge is a hard slog, a noisy process which takes 9 steps back for every 10 steps forward. One of the the main issues is to guard against the creeping advance of error in the service of ideology. Creationism is one such error. The leap from Athenian Greece to modern democracy, and glossing over republican & imperial Rome, Christianity and the medieval period, is another such error. Natural science has the world around us to keep us honest, but the human sciences relies upon our own good will, sincerity and due diligence. Let's not be stupid.