The simple term "christian principles" is a ridiculous notion. All matters referencing moral law can be branched accross all of the major religous groups. So to say in absolution that the U.S. was founded on "christian principles" is ignorant. You could say the same for any number of countries. It is a propaganda phrase to appeal to the ignorant people who assume that christianity is the "supreme and right" religion. If you keep your mind open you would see that most religion is based on the same moral code of conduct. This being said I would hope that; even though they were not as educated as most today; our founding fathers would have thought in advance about the possiblities of people of different religous background to there own would be in our country one day.