John Adams is probably the most Unitarian in American History. Yet annoying my attempt to find out which kind he was have proven fruitless.

There are I know at least three different Positions on Jesus that exists among those who self identify as Unitarians.

1. Arianism which still views as being Pre-existence but not Co-Eternal with The Father.
2. Socinianism which denies the Pre-Existence but still views Jesus as as the Son of God from the beginning including a Virgin Birth.
3. "Strict Unitarianism" which generally denies Jesus any kind of Divinity.

I'm curious because when I engage in discussions about the Religious Beliefs of the Founding Father I want to be precise and nuanced and not make the sweeping Generalizations people on both sides tend to make.

And I feel those who want to also label Adams a Deist only have any case if he was the third option. Each of the first two involve a post Creation Divine intervention.