John Marshall is the legendary figure who played a crucial role in shaping the American Constitutional law. He was responsible for making the Supreme Court of the United States an important institution along with legislature and executive. He was the leader of the Federalist Party in Virginia and also served in the United States House of Representatives. He is one of the longest serving Chief Justices and the fourth longest-serving justice in the history of the US Supreme Court. As a lawyer, he was well-versed in the subject and played a dominant role as a judge for over a period of three decades. He is credited with elevating the position of the American judicial system and making it an independent body. He stressed on the importance of Federal Laws over State Laws. One of the greatest admirers of George Washington, Marshall also served in the American military during the American Revolutionary War. As an immensely loyal Federalist, Marshall saw the Constitution as an instrument of national unity and federal power. He served as Chief Justice of the Supreme Court during the administrations of six Presidents - John Adams, Thomas Jefferson, James Madison, James Monroe, John Quincy Adams and Andrew Jackson.