An American presidential election season brings an increase in the assertions that the United States was founded as a Christian Nation. Such statements assume that the founding generation in the U.S. agreed that it was (and ought to be) dedicated to Christianity, and that their conviction was subsequently abandoned. Discussion over this issue often focuses on how to understand the separation of church and state. Did the separation intend to protect the state from Christianity or to shield religion from the state?
The founding generation took a position on whether they had erected a Christian polity, stating unequivocally that "the United States of America is not in any sense founded on the Christian Religion." This statement appeared in the Treaty with the Barbary States, which the U.S. Senate ratified in June, 1797. The treaty, negotiated during the presidential administration of George Washington, was ratified while his hand-picked successor John Adams held the presidency. It offers a clear and direct statement on the question.
Even more telling for our contemporary fears and debates, the statement was offered in direct relation to the existence of the Islamic faith and the desire of the U.S. government to interact peaceably with states that adhered to that faith. Using the term "Musselmen" for "Muslim," the treaty went on to state that the United States "has in itself no character of enmity against the laws, religion or tranquility of Musselmen." It proudly pointed out that the United States "never have entered into any war or act of hostility against any Mehomitan nation," (by which they meant followers of the prophet Mohammed). Finally, it declared that religious differences would never be used as a "pretext" to interrupt "the harmony existing between the two countries." Reading this early treaty in the context of modern U.S. political policy, it is a pretty clear that we are in flagrant violation of the treaty' promises. For the text quoted here see Article 11 of the treaty, reproduced at: http://avalon.law.yale.edu/18th_century/bar1796t.asp.
The United States negotiated and signed this treaty as part of a project of expanding its trade into the Mediterranean region. Kicked out of the British Empire, the United States desperately needed commercial partners, and it eagerly turned to the Barbary States of North Africa for trade and alliance. These states included a number of separate polities, all of them under the Ottoman Empire and all of them officially adhering to Islam. Their location on the southern coast of the Mediterranean Sea meant they were well placed to participate in both trade with and piracy against Christian Europe. For centuries, southern Europeans enslaved captives from these states, and Barbary Muslims similarly enslaved captives from Christian Europe. (Many charitable organizations in Catholic Europe worked to redeem the captives, by paying a fee for their return.) The United States wanted a piece of the trade without getting entangled in the captivity and slavery that remained a feature of European and Barbary relations.
The United States, believing it was founded on different principles, aimed to rise above the religious rivalries of the Mediterranean world. Hence it confidently asserted that the United States was in no sense founded as a Christian Nation. The U.S. represented a new nation, established on new principles based on the Enlightenment. Since that time, we have fallen into older rivalries. It is no surprise we employ older rhetoric as well. The founders hoped for a different future.