When the Constitutional Convention met in Philadelphia in 1787, the delegates met under conditions of strict secrecy so they could speak freely. There is therefore no complete record of what was said in the Convention by the delegates; most of what is known about the Convention comes from notes made by the delegates about the content and nature of the discussions there. This account comes from Robert Yates, a delegate from New York who was strongly opposed to a new constitution, who became a vocal Antifederalist opposed to ratifying the document the convention produced. He believed that the delegates to the convention lacked the authority to change the Articles of Confederation, so he left the Convention in July 1787.