Courtesy of the June 10, 2005 D.C. Political Report:

Two hundred and eight years ago today, President John Adams (F-MA) signed the Treaty of Tripoli. Three days earlier the U.S. Senate had unanimously approved the treaty. Why is this important today? Because Article XI of the treaty was a proclamation that the "Government of the United States of America is not in any sense founded on the Christian Religion…." Upon signing the treaty Adams issued a statement which said, "Now be it known, That I, John Adams, President of the United States of America, having seen and considered the said Treaty do, by and with the advice and consent of the Senate, accept, ratify, and confirm the same, and every clause and article thereof."