> How much was Jefferson influenced by the writings of Rousseau, in particular
> the Social Contract?  I am asking because I was just at a seminar that
> hypothesized that the success of the American Revolution was due to
> Jefferson's political beliefs and his moral beliefs.  The French Revolution
> was so utterly violent resulting in the Reign of Terror because it was
> founded on the philosophy of Rousseau.  From skimming the Social Contract
> there seems to be a lot of overlap in Jefferson's and Rousseau's thoughts.

Jefferson may have been influenced in some general sense by Rousseau, but he
made little mention of Rousseau, and omitted him from particular lists
relative to government.  For example, he wrote to John Norvell in 1807:

"I think there does not exist a good elementary work on the organization of
society into civil government: I mean a work which presents in one full and
comprehensive view the system of principles on which such an orgnization
should be founded, according to the rights of nature.  For want of a single
work of that character, I should recommend Locke on Government, Sidney,
Preiestley's Essay on the first Principles of Government, Chipman's
Principles of Government, and the Federalist.  Adding, perhaps, Beccaria on
crimes and punishments..."

In a letter to Henry Lee written in 1825, Jefferson discusses the origins of
the Declaration of Independence, and writes:

"Neither aiming at originality of principle or sentiment, nor yet copied
from any particular and previous writing, it was inteneded to be an
expression of the American mind, and to give to that expession the proper
tone and spirit called for by the occasion.  All its authority rests then on
the harmonizing sentiments of the day, whether expressed in conversation, in
letters, printed essays, or in the elementary books of public right, as
Aristotle, Circero, Locke, Sidney, Etc."

Since Rousseau had been dead for some time, it would seem that if Jefferson
had thought highly of the Social Contract and was influenced by it, he would
have mentioned it in the above lists.  He was familiar with the writings of
Rousseau, of course, and had some of his works in his library.  But he seems
to have mentioned him only rarely, and not that I know of as an influence on
his thinking about politics and government.  It probably would make an
interesting study to see how much of Rousseau's thought seems to be
reflected in Jefferson's ideas on government, but I don't know of such a
study.  Garry Wills, in his Inventing America: Jefferson's Declaration of
Independence, examines phrase by phrase the Declaration and indicates
possible sources, some of which were never mentioned specifically by
Jefferson (such as Hutcheson, as I recall).  I don't own the Wills book,
but you might check on that to see if he attributes any of the Declaration
to Rousseau.  And, of course, the books of Peterson on Jefferson might
contain some references to Rousseau, as well as other historians writing on
Jefferson.  But if there was an influence, it does no appear that Jefferson
thought it was great enough to mention himself.