"As the Government of the United States of America is not, in any sense, founded on the Christian religion; ..." the Treaty of Tripoli, 1797
"The purpose of separation of church and state is to keep forever from these shores the ceaseless strife that has soaked the soil of Europe in blood for centuries." -1803 letter objecting use of gov. land for churches, James Madison
I don't like it when people say that the founding fathers were Christian or that America is a Christian nation. Many of the founding fathers of America were Deists, not Christians. This is why a lot of people get confused. When Benjamin Franklin or Jefferson mention God or virtue or value, they tend to automatically think that they were talking about Christianity. It was actually a mixed bag, but the majority opinion was to be secularists. Thomas Paine and Thomas Jefferson were probably the least religious, bordering on atheism.
Taken from the Wikipedia article:
Deism is the belief that a supreme God exists and created the physical universe, and that religious truths can be arrived at by the application of reason alone, without dependence on revelation. It is in contrast with fideism, found in many forms of Christianity, Islamic and Judaic teachings, which holds that religious truths rely upon revelation in sacred scriptures and upon the testimony of other people as well as reasoning.
Deists typically reject most supernatural events (prophecy, miracles) and tend to assert that God has a plan for the universe, which he does not alter by intervening in the affairs of human life nor by suspending the natural laws of the universe.
Here are some quotes from some of the Founding Fathers:
". . . Some books against Deism fell into my hands. . . It happened that they wrought an effect on my quite contrary to what was intended by them; for the arguments of the Deists, which were quoted to be refuted, appeared to me much stronger than the refutations; in short, I soon became a thorough Deist." - Benjamin Franklin
"I wish it (Christianity) were more productive of good works ... I mean real good works ... not holy-day keeping, sermon-hearing ... or making long prayers, filled with flatteries and compliments despised by wise men, and much less capable of pleasing the Deity." -Benjamin Franklin
"I almost shudder at the thought of alluding to the most fatal example of the abuses of grief which the history of mankind has preserved-- the Cross. Consider what calamities that engine of grief has produced!" -letter to Thomas Jefferson, John Adams
"Gouverneur Morris had often told me that General Washington believed no more of that system (Christianity) than did he himself." -Thomas Jefferson, in his private journal, Feb. 1800
"What is it the New Testament teaches us? To believe that the Almighty committed debauchery with a woman engaged to be married; and the belief of this debauchery is called faith." -Thomas Paine
Now there is this link that has a lot of Christian quotes from them. I would judge any quote that does not directly mention the Bible or Jesus very carefully. It could just be in reference to Deism. http://christianparty.net/christianationquotes.htm
But here are some more that might make you think differently.
"I have recently been examining all the known superstitions of the world, and do not find in our particular superstition (Christianity) one redeeming feature. They are all alike founded on fables and mythology." - Thomas Jefferson
"It has been fifty and sixty years since I read the Apocalypse, and then I considered it merely the ravings of a maniac." - Thomas Jefferson
"The way to see by faith is to shut the eye of reason." -Thomas Jefferson
Just because there are Christians in America does mean that the country has to be a Christian nation. I'm on the side of the Constitution and the Treat of Tripoli. I'm not trying to get the founding fathers on my side but I am trying to show you something that can be construed quite easily. I just wanted to show the other side.