Rather than rehash this endlessly with others, here are some keywords for anyone interested in the dissenter/Unitarians of the Revolutionary era: Joseph Priestley, Thomas Jefferson, Ben Franklin,Theophilus Lindsey, William Ellery Channing, Unitarian.
Catholics alway kept a ken eye out for heretics and the Catholic encyclopedia of 1905 has a remarkably fair account of the history of Unitarianism in America and elsewhere here.
Unitarianism is important because it is one half of the equation which created the liberal/conservative split in American politics. Harvard was Unitarian and "liberal". Yale was Calvinist and "fundamental" or conservative.
Harvard won that battle. But Unitarian Christianity lost its soul--Unitarians today, except for a very few here and there, are not Christian at all. They are marxists, statists, new-agers, Buddhists, Wiccans or whatever.