The 1797 Treaty of Tripoli is the source of Washington’s supposed statement. That treaty, one of several with Tripoli, was negotiated during the “Barbary Powers Conflict,” which began shortly after the Revolutionary War and continued through the Presidencies of Washington, Adams, Jefferson, and Madison. The Muslim Barbary Powers Tunis, Morocco, Algiers, and Tripoli were warring against what they claimed to be the “Christian” nations England, France, Spain, Denmark, and the United States. In 1801, Tripoli even declared war against the United States, thus constituting America’s first official war as an established independent nation.
Throughout this long conflict, the four Barbary Powers regularly attacked undefended American merchant ships. Not only were their cargoes easy prey but the Barbary Powers were also capturing and enslaving “Christian” seamen in retaliation for what had been done to them by the “Christians” of previous centuries e.g., the Crusades and Ferdinand and Isabella’s expulsion of Muslims from Granada.
In an attempt to secure a release of captured seamen and a guarantee of unmolested shipping in the Mediterranean, President Washington dispatched envoys to negotiate treaties with the Barbary nations. Concurrently, he encouraged the construction of American naval warships to defend the shipping and confront the Barbary “pirates” a plan not seriously pursued until President John Adams created a separate Department of the Navy in 1798.
The American envoys negotiated numerous treaties of “Peace and Amity” with the Muslim Barbary nations to ensure “protection” of American commercial ships sailing in the Mediterranean. However, the terms of the treaty frequently were unfavorable to America, either requiring her to pay hundreds of thousands of dollars of “tribute” i.e., official extortion to each country to receive a “guarantee” of safety or to offer other “considerations” e.g., providing a warship as a “gift” to Tripoli, a “gift” frigate to Algiers, paying $525,000 to ransom captured American seamen from Algiers, etc.. The 1797 treaty with Tripoli was one of the many treaties in which each country officially recognized the religion of the other in an attempt to prevent further escalation of a “Holy War” between Christians and Muslims. Consequently, Article XI of that treaty stated: