As the government of the United States is not, in any sense, founded on the Christian religion; as it has in itself no character of enmity against the laws, religion or tranquility of Musselmen [Muslims] … it is declared … that no pretext arising from religious opinion shall ever product an interruption of the harmony existing between the two countries.
The Treaty of Tripoli (January 4, 1797), written by Joel Barlow, carried unanimously by the U.S. Senate and signed into law by President John Adams.