After several years of comparatively weak government under the Articles of Confederation, a Constitutional Convention in Philadelphia proposed a new constitution on September 17, 1787, featuring a stronger chief executive and other changes. George Mason, a Constitutional Convention delegate and the drafter of Virginia's Declaration of Rights, proposed that a bill of rights listing and guaranteeing civil liberties be included. Other delegates—including future Bill of Rights drafter James Madison—disagreed, arguing that existing state guarantees of civil liberties were sufficient and any attempt to enumerate individual rights risked implying the federal government had power to violate every other right (this concern eventually led to the Ninth and Tenth Amendments). After a brief debate, Mason's proposal was defeated by a unanimous vote of the state delegations. In the final days of the convention, North Carolina delegate Hugh Williamson proposed a guarantee of trial by jury in federal civil cases, but a motion to add this guarantee was also defeated.