No. There have been Presidents with no affiliation, Methodists, Unitarians as well as Catholic and Protestant. Nixon, who was Republican, was a Quaker.
It's only been in the last two Presidential elections that so much has been made of a person's religious beliefs, even though the Constitution says there should not be any religious test for a candidate.
Well, Mormons think they ARE Christians, but I know that is not universally accepted. Have you looked in to their beliefs? Accepting your premise, for the purpose of this discussion, that they are not, he would not be the first non-Christian.
Thomas Jefferson comes to mind. He was a Deist, as were several of the founding fathers. How significant it is I guess would be a personal matter.
As far as historically, I would think not very momentous at all.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.