American copyright law has undergone an unappreciated conceptual transformation over the course of the last century. Originally conceived of as a form of private law—focusing on horizontal rights, privileges, and private liability—copyright law is today understood principally through its public-regarding goals and institutional apparatus, in effect as a form of public law. This transformation is the result of changes in the ideas of law and lawmaking that occurred in American legal thinking following World War II, manifested in the deeply influential philosophy of the Legal Process School of jurisprudence which shaped the modern American copyright landscape. In the Legal Process conception, determining the substantive content of the law is fundamentally a matter of identifying the institution with formal competence (and legitimacy) to decide the matter, and then deciphering its policies and directives for an area of law in a purposive manner. The heyday of the Legal Process School, the 1950s and 1960s, coincided with the period during which the current U.S. copyright regime was being constructed. Several of its core lessons find direct veneration therein, including: the centrality of legislation as the harbinger of copyright’s policy and purposes; the primacy of collectivist copyright policy over individual copyright principles; a recognition of the limitations of courts and judge-made law; and the treatment of copyright as a specialized but autonomous body of law requiring expert administration. As this Article argues, the U.S. copyright regime is today better conceived of as a “legal process,” wherein the law is dynamic, purposive, and multi-institutional in origin. Modern copyright thinking would do well to embrace this reality and develop mechanisms to deal with this fundamental—yet unacknowledged—transformation, which explains a variety of perceived anomalies and puzzles within the working of the system.