Geoffrey Stone, University of Chicago professor of constitutional law, delivered this lecture to refute the frequent contemporary assertions of the Christian Right that America was founded as a Christian nation. The lecture is 43 minutes followed by 19 minutes of good Q/A. I had planned to look into this topic someday and was glad to get the RSS feed that led to my listening to the whole thing and feeling it was time well spent.
Stone quotes extensively from the writings of Franklin, Jefferson, Adams, Washington, and Payne to show that, while only Payne was openly hostile to Christianity, none was a practicing Christian or active in any church. All subscribed to Deism, which was a rational, scientific view of a non-interfering Creator that developed in the Enlightenment movement, the same Enlightenment that produced the ideas that colonies might declare their independence from a king and create a republican nation in which the people were declared sovereign. Stone also discusses the views of other Founding Fathers but in less detail.
There are references in the Declaration of Independence, penned mostly by Jefferson, that refer to a supreme being, but the words used, such as "providence," are typical of Deism terminology. None of the traditional ways of referring to the Christian God are used at all, and certainly there is no reference to Jesus, whose divinity was uniformly rejected by Deists, as they rejected many other core Christian doctrines.
At a difficult moment in the Constitutional Convention, Franklin suggested that they all pause and pray, but this suggestion was rejected by silence.
In America's first treaty, with the Bey of Tripoli, in 1796, this statement appears in Article 11:
As the government of the United States of America is not, in any sense, founded on the Christian religion; as it has in itself no character of enmity against the laws, character, or tranquility, of Mussulmen; and, as the said States never entered into any war, or act of hostility against any Mohometan nation, it is declared by the parties, that no pretext arising from religious opinions, shall ever produce an interruption of the harmony existing between the two countries.
This treaty was read aloud to the Senate and unanimously approved.
Those who argue America was founded as a Christian nation are able to find evidence of a great deal of Christian religious fervor as early as about 1800, which was the approximate beginning of the Second Great Awakening. But the participants in that were a younger generation, motivated in substantial part by the horrors of the French Revolution and the suspicion that they arose precisely because of the secularization of France. Several of the Founding Fathers expressed their dismay at the religiosity of the Second Great Awakening.
In the lecture and QA, Stone deals with many related issues including the meaning of the First Amendment, the fact that 11 of 13 States had established religions at the time the Constitution was ratified, what citizens thought about Christianity and how that might affect the meaning of the First Amendment, etc. Stone seems to be aiming this scholarship at judicial "originalists" who try to interpret the Constitution by figuring out what the Drafters would have thought about an issue, if they had thought about it.