Many well-meaning Christians argue that the United States was founded by Christian men on Christian principles. Although well-intentioned, such sentiment is unfounded. The men who lead the United States in its revolution against England, who wrote the Declaration of Independence and put together the Constitution were not Christians by any stretch of the imagination.
This is a very well presented argument proving the early intention of the Founding Fathers to separate Church and State. It’s a fairly quick read, I recommend it.