With Franklin ill, Morris opened the proceedings of the Philadelphia Convention on May 25. His motion to nominate Washington as chairman of the convention was backed by a unanimous vote. Morris consistently attended the meeting of the convention, but rarely spoke after the first day, instead allowing lawyers and others more experienced with the law to debate various issues. His primary goals, including a provision ensuring the federal government had the power to lay tariffs and taxes, were shared by the vast majority of delegates at the convention. On September 17, Morris signed the final document produced by the convention which, rather than amending the Articles, was intended to supplant the Articles as the new Constitution of the United States. Morris was one of just six individuals to sign both the Declaration of Independence and the United States Constitution.