George Washington was a great leader/man at his time. Overall though, I would say his best trait was his moral leadership. Washington had high enough morals to refuse positions after the revolutionary war that could have eventually led him to being a dictator in America; he could have taken full control of the continental army, but refused and kept his support for the American government. In later years during his presidency, Washington also proved to have high morals when he gave up his presidency, and the power that came with it, after two terms even though there was not yet a term limit.
