Whether you like it or not, 70% of Americans are Christians, thus making us by definition a Christian nation, even though we may have the separation of church and state and the freedom of religion, most people here are Christians, and if you don't like it move some place else.
I mean no disrespect, but go read what they wrote! And not just little bits of what they wrote (quote mining) but whole works. Go read the 15 Continental Congress proclamations! No really, go read them: http://memory.loc.gov/cgi-bin/ampage?collId=bdsdcc&fileName=05701//bdsdcc05701.db&recNum=0&itemLink=r?ammem/bdsbib:@field%28NUMBER+@od1%28bdsdcc+05701%29%29&linkText=0&presId=bdsbib
After you read them, get back to me. America was founded on Christianity and it will be destroyed for it's departure from it.
Just for the simple fact that the majority of people claim to be Christian. However, the country was not founded on the basis of Christianity. It was founded because people back then did not want to be ruled by the English government anymore. So, saying America is a "Christian nation," usually means that Christians have ulterior motives, when they say such things.
The country was founded partially in the name of religious freedom. Although it may have been because of different denominations of Christianity, the sentiment is the same. People should have the freedom to choose. Additionally, the cultures of America are diverse enough to make a country united under one religious standpoint impossible.
The United States is not a theocracy. Among our most important freedoms is the freedom of religion. We can be considered a place of choices (at least regarding beliefs and the like). No single religion defines this country, and that is one of the things that makes it what it is.
Many people would love to call America a Christian nation, but because of its embrace of religious freedom, it really shouldn't be considered inherently Christian. I am a non-Christian in America and it is undoubtedly difficult to explain to some people that I have no interest in attending their Christian church.
It is true that some of the founding fathers were Christians. It is also true that most Americans would identify as some species of Christian. What is also true is the religiosity is in decline. Also, America has a long and glorious tradition of the separation of church and state. I see little upside to the designation of America as a Christian nation.