Assessment of the authorship evidence for two famous sets of Anti-Federalist essays from the New York ratification debate of 1787-88 indicates the role of the opposition to the Constitution at the June 1788 ratifying convention dominated by the Anti-Federalists. Because the contest in New York was so vital and close, public debate in the months leading up to the ratifying convention was rich and varied. In this debate, conducted mostly under pseudonyms, prominent roles were played by the essays of 'Cato' and 'Brutus.' The authorship of these writings, seemingly unknown to contemporary readers, has continued to baffle generations of historians. This essay contends that John Williams, an influential political leader from Salem, New York, wrote both the Cato and the Brutus essays.