Jefferson on Income and Sales Taxes

"For example. If the system be established on basis of Income,
and his just proportion on that scale has been already drawn
from every one, to step into the field of Consumption, and tax
special articles in that, as broadcloth or homespun, wine or
whiskey, a coach or a wagon, is doubly taxing the same article.
For that portion of Income with which these articles are purchased,
having already paid its tax as Income, to pay another tax on the
thing it purchased, is paying twice for the same thing; it is an
aggrievance on the citizens who use these articles in exoneration
of those who do not, contrary to the most sacred of the duties of a
government, to do equal and impartial justice to all its citizens."

-- Thomas Jefferson (letter to Joseph Milligan, 6 April 1816)

Reference: The Writings of Thomas Jefferson, Memorial Edition,
Lipscomb and Bergh, eds., vol. 14 (465)