A slanted and fact-free response. Given that a show of piety is essential for anyone wanting the votes of the masses, I would have thought Americans might be the last people to ask about that deception.
I don't think you have claimed this exactly, but is it really important to you that there has 'never been an atheist president'?
Part of the problem is the loaded term 'atheist'. I identify with the word myself because it describes the way I live my life, but as I mentioned earlier I don't like it because it defines me in terms of others' crazy ideas. I am more than just a lack of crazy ideas (and I have other unrelated ideas that are definitely crazy). You can put many public figures who have no belief in a deity in that same category, Einstein probably being the most famous. Even Richard Dawkins resists the term somewhat, putting himself at 6 on his scale of 1-7.
Meantime, that lack of intellectual satisfaction at not having explanations for our existence makes it difficult to analyse non-belief too far into the past. How did all this stuff come to be here? A deist god is the placeholder 'explanation' until you have Big Bang cosmology and evolution by natural selection. We know that all the stuff in the universe is borrowed from the expansion of space-time, and that the living things fittest to survival and reproduction tend to pass on their ever-mutating genes, but that was all unavailable to the desperately curious before the last part of the 19th Century. So almost everyone was at least a deist.
Here is some speculation on the closeted atheist presidents, but they could have done themselves a favour by calling them the 'nones', in which category you would include most intellectually curious deists from the past, but not all.
Their list of definite (based on their analysis of blasphemous quotes) non-believers: Jefferson, Lincoln, Grant, and Taft.
Their suspects for closeted status, based on less compelling evidence: Harrison, Tyler, Hayes, Arthur, Kennedy, Nixon, Hoover, Reagan, Clinton, and Obama.
Stuart
Lincoln was no "unbeliever". He very clearly "believed" and infact... merely removed himself from the brick and mortar establishment. If you don't see Christian Principles in Lincolns actual writing and leadership... you're deceiving yourself and believing propaganda put out by intellectual morons that have no desire to ponder what proves that they are dwarfed by a "higher power".
Abe at Fort Sumter
"“I charge the whole guilt of this war upon the ambitious, educated, plotting leaders of the South.… A day will come when God will reveal judgment and arraign these mighty miscreants.… And then these guiltiest and most remorseless traitors … shall be whirled aloft and plunged downward forever and ever in an endless retribution.”"
Oh... and Jefferson...
""Question with boldness even the existence of a god; because, if there be one, he must more approve the homage of reason, than that of blindfolded fear."
- In Query XVII of Notes on the State of Virginia,
You are misrepresenting T.J., as well.
In full response to each person you cited as "not being a Christian"... they simply disliked attending services and thus the assumption is made that they weren't "servants" of Jesus.
These men resisted the rule of Theocracy... not Jesus. Speculation... alone... could ever say those men were "unbelievers".