"I rejoice that in this blessed country of free inquiry and belief, which has surrendered its conscience to neither kings nor priests, the genuine doctrine of one God is reviving and I trust that there is not a young man now living in the United States who will not die a Unitarian."
--Thomas Jefferson June 22, 1822
Unitarians such as Jefferson, John John Quincy and Abigal Adams,Julia Ward Howe and Millard Fillmore, among others, did consider themselves Christians.
Unitarians Christians? (ok don't flame me!)
But that was at the end of his life, not during the relevant times of country building.