For those intent on believing the fiction that the United States was founded as a Christian nation, I give you The Treaty of Tripoli:
The Treaty of Tripoli, 1797, Article 11, as ratified by Congress:
Art. 11. As the Government of the United States of America is not, in any sense, founded on the Christian religion; as it has in itself no character of enmity against the laws, religion, or tranquillity, of Mussulmen; and, as the said States never entered into any war, or act of hostility against any Mahometan nation, it is declared by the parties, that no pretext arising from religious opinions, shall ever produce an interruption of the harmony existing between the two countries.