Most of the literature on this country’s Founding Era concludes that at least in the very early years, the Founders did not look to original intent to construe the Constitution. However, this study looks not at what the Founders said they believed, but how they acted. In the First Federal Congress, the members did use arguments based on original intent. This study identifies their originalist arguments and categorizes them into five rhetorical categories. It concludes that these arguments did not dominate the debates, but were one type of argument among many.