John Adams: “The government of the United States of America is not in any sense founded on the Christian religion.” (Treaty of Tripoli, 1797)
Thomas Jefferson: “Christianity neither is, nor ever was, a part of the common law.” (Letter to Dr. Thomas Cooper, February 10, 1814)
James Madison: “The civil government … functions with complete success … by the total separation of the Church from the State.” (Writings, 8:432, 1819)
George Washington: “If I could conceive that the general government might ever be so administered as to render the liberty of conscience insecure, I beg you will be persuaded, that no one would be more zealous than myself to establish effectual barriers against the horrors of spiritual tyranny, and every species of religious persecution.” (Letter to the United Baptist Chamber of Virginia, May 1789)