In the 1930s, American economists vigorously debated how to introduce students to the field of economics. Different ideas about the best first course reflected both theoretical and methodological disputes within the field and different conceptions about the purpose of economics instruction in students' education and the relation of economics to other social science disciplines. The disputes translated into a proliferation economics textbooks none of which dominated the market or served as a model for the field. By the 1950s, all of this changed. Economists continued to discuss the first course, but concerns focused on relatively narrow issues like the proper order of topics and the number of equations and graphs. Samuelson's text dominated and set the standard for competitors. This paper will examine how this transition happened and the consequences for the discipline.