We have the greatest opportunity the world has ever seen, as long
as we remain honest which will be as long as we can keep the
attention of our people alive. If they once become inattentive to
public affairs, you and I, and Congress and Assemblies, judges and
governors would all become wolves.
Thomas Jefferson to Edward Carrington, 1787. ME 6:58
He was the greatest of the Founding Fathers.
He authored the Declaration of Secession (ie Independence) and championed the cause of liberty and the principle that government derives its legitimacy from the consent of the governed.
He fought against the centralization of power and was clearly correct in identifying the tendency of government - to seek to centralize power and concentrate it into ever fewer hands to the detriment of liberty.