5. James Madison
Madison was the leading figure during the Constitutional Convention, and the author of the Bill of Rights, though he borrowed liberally from fellow Virginians when he prepared them for submission. During his presidency he became the first American president to petition Congress for a declaration of war, and he exercised his powers as commander in chief in civilian garb, setting a precedent which remains the norm two centuries later. The Constitution was the work of many men, but it was Madison who drove the convention, and who later successfully argued for ratification.