Well you can see from my post #70 ( http://www.freerepublic.com/focus/f-news/2546951/posts?page=70#70
that Abigail Adams self-identifies as "Unitarian" in an 1816 letter. Granted, this is long after the declaration of independence and also after her husband's Presidency, but it is prior to the 1819 date that Achilles cited for Unitarians seeing themselves as a seperate movement.
The basic point for me that it appears the Adams' church parish adopted a Unitarian philosophy by the 1750s, and that both John and Abigail were registered members of that parish and financially supported it and agreed with the church's teachings.
As for whether specific Unitarian idealogy developed later, I can't say. While I don't mean to insult anyone on FR, though, it seems to me the only "dististive" belief that Unitarianism has is that they DON'T have any specific beliefs!
It is my understanding that a buddhist, an agnostic, a Christian, and maybe even an atheist could join a Unitarian church and become members in good standing with their beliefs. Unitarians profess that they don't have the answers, only that they reject the idea that traditional Christian teachings are certain truth. Some Unitarians still self-identify as "Christian" (as in the "Jesus is my role model in life" sense), but even many of them would probably say they don't accept the traditional Christian beliefs of the trinity, resurrection, etc.
It appears to me that the Adams', while nominally "believers" in Jesus, rejected the idea that he was divine and the rest of mainstream Christian beliefs. That makes their church "Unitarian" in my eyes as well as theirs. Traditional Christianity -- mainstream Catholics, Protestants, and Orthodoxy, wouldn't consider Unitarianism to be Christian. And it certainly isn't related to Mormonism or anything else that has a distinctive set of ideas about Jesus. The fact Unitarians are silent on religious questions and tell members they can believe whatever they want is the core basis of Unitarianism, in my view. It's why they were no longer accepted as a part of traditional protestant churches.
The Green Party may not be "socialist" on paper, but an overview of their platform makes it clear to anyone that reads it that they subscribe to a socialist idealogy.
So we can debate over the details of exactly how and when the Unitarian church was established as a separate denomination, but it seems clear to me that the Adams' family believed in Unitarianism.
My only contact with the Unitarian “church” (other than a girlfriend of many years ago) came when I visited a church sale of theirs. I was struck by the distinctive “look” of most of the people there, which I can’t put my finger on. They didn’t look like stereotypical hippies or leftists, but they didn’t look like typical suburban middle-class Americans either.
You are conflating various views that eventually became “Unitarianism” with the word “unitarianism”. Unitarianism combined several heretical doctrines besides having a similar sort of Christology as, say Arians. Unitarians, for example, rejected the notion of original sin. But one of the biggest mistakes people make is that they somehow think that what passes for Unitarianism today is what it was originally.
Unitarians claimed that they were Christian, and the arguments that others had with them were over matters of systematic theology that historically fell within Christian boundaries. It was only a very long time later that Unitarianism morphed into essentially nothing (”What do you get when you cross a Jehovah’s Witness with a Unitarian? Someone who knocks on your door but isn’t quite sure why.”)In fact, the early Unitarians were very Old Testament oriented compared to modern evangelicals.
John Adams was a Bible thumping Christian (just read what he has to say about God and the Bible). He may have had a low Christology by 1800, but there is no evidence at all that he rejected Original Sin, etc. Again, there were no Unitarian signers of the Declaration - not Unitarian in the original meaning of the term, and certainly not in the modern meaning of the term.
Regarding the list...I should also add that identifying anybody as an Episcopalian/Congregationalist is an absurdity. These are exactly opposite ecclesiologies. As for claiming Jefferson in 1776 was a “Deist”, I don’t know of any evidence for it in 1776. Those who argue Jefferson was a deist usually claim that it was the result of his time in France, which was well after the Declaration.