Final answer:
George Washington established the precedent of a policy of neutrality for the United States in international conflicts during his presidency, which is a significant part of American foreign policy history.
Step-by-step explanation:
Among the precedents set by George Washington as the first President of the United States, he declared a policy of neutrality in international affairs. This action in 1793, known as the Neutrality Proclamation, positioned the United States to remain neutral in the conflict between France and Great Britain, thus expanding his role as diplomat-in-chief. Unlike some beliefs that he encouraged the development of a two-party political system, Washington actually warned against political parties in his farewell address. He did not issue an embargo act against foreign countries nor did it have anything to do with the establishment of judicial review in the Supreme Court, which came later with the landmark case Marbury v. Madison in 1803. Thus, the correct answer to the question regarding the precedent set by Washington during his presidency is C) Declared a policy of neutrality.