American legal scholars spend a large proportion of their time debating and theorizing procedure. This Article focuses on American proceduralism in the particular field of civil justice and undertakes a detailed comparison with England, where procedural questions receive little academic attention. It finds that procedure is more prominent in America partly because Americans have been more willing than others to use private litigation as a tool for regulation. More significantly, procedural questions necessarily occupy more space in American debates because authority over civil justice is unusually dispersed among different actors; procedural rules allocate power among these actors. But American proceduralism runs deeper than these surface explanations allow, and a full account requires an examination of the history of American legal thought. I trace contemporary American proceduralism to a counter-intuitive source: the emergence of Legal Realism in the 1920s and 1930s.