1796 CE: TREATY WITH TRIPOLI (1796), ARTICLE 11

“The Government of the United States of America is not, in any sense, founded on the Christian religion.”

This portion of the treaty – meant to calm the Muslim nation of Tripoli – has often been cited by strict separationists of Church and State.
(Author – And so it should be)

The treaty was approved unanimously by the United States Senate and was printed in the Philadelphia Gazette and two NY papers with no evidence of any dissent. [See book by Frank Lambert (February 3, 2005) Introduction: The Founding Fathers and the Place of Religion in America. Princeton University Press]