The patent system is in flux. Concerns abound about the imperfect fit between traditional patent rights and the Information Age, excessive numbers of patents, overbroad patent rights, poor patent quality, and allegedly exploitative actors, like so-called “patent trolls.” In response, courts, commentators, and Congress have proposed, debated, and sometimes adopted a series of reforms and changes to patent rights, patent doctrines, and patent institutions. The America Invents Act of 2011 (AIA) introduced the most significant changes to the patent system since 1952 and was even described by one commentator (hyperbolically, as we will see) as “the most significant overhaul to our patent system since the founding fathers first conceived of codifying a grand bargain between society and invention.” The Supreme Court’s recent renewed interest in patent law has also resulted in significant changes, including abolishing the long-standing rule that “a patent owner is entitled to permanent injunctive relief once a patent is adjudicated to be both valid and infringed.”And scholars have proposed a variety of other significant changes to American patent law.

With change, comes opposition. The changes and proposed changes to patent law have sparked vigorous policy debates about the effects on the patent system’s goals of promoting innovation and preserving competition. But beyond policy disagreement, opponents also are concerned that recent changes and proposed changes reflect a sharp, dramatic break with long-standing, fundamental aspects of the patent system. To them, departing from the historical features of the patent system is inadvisable, illegitimate, or even unconstitutional.

This Essay provides context necessary to evaluate these concerns. Recent changes and proposed changes seem like a dramatic and sharp break with past practice precisely because the patent system has been remarkably stable since the middle of the 19th century. To many in the patent community, this contention may seem surprising, or even laughable, given widespread recognition of significant adjustments and fluctuations in the patent system over the years.The patent system certainly undergoes doctrinal variations at the operational level of applying patent law’s specific requirements to determine if particular patents are valid and infringed—for example, the specific tests used or defenses available.There also have been changes in how the patent system is used over time, including the volume of patenting and patent enforcement activity.

But at a foundational or systemic level, the nature of the rights granted, the institutional structure of the patent system, and the basic doctrines of patentability, infringement, and remedies have remained largely constant. It is exactly because the foundational and systemic aspects of the patent system have been so constant that the fluctuations in doctrinal implementation seem so significant. For example, the proper test for determining whether an invention is too obvious to warrant a patent, much debated in the patent community, would seem relatively minor compared to a reform requiring the Patent Office to decide whether to issue a patent based on a case-by-case determination of whether the innovation benefits of a particular patent outweigh its social costs. Even the question of when inventions are patent ineligible abstract ideas, laws of nature, or natural phenomena—probably the most contested current patent issue—would become much less significant if Congress started debating abolishing patents for some industries, imposing price controls on patented products, setting mandatory licensing terms, or replacing the private right of action for patent infringement with government enforcement.

But long-standing stability in the foundational and systemic characteristics of the patent system does not mean that these characteristics are inevitable, necessary, or mandatory features. To the contrary, in the first few decades of the American patent system, there was significant change, experimentation, and development in the nature of patent rights, the patent system’s institutional structure, and the basic doctrines of patent law. The foundational and systemic aspects of the patent system that persist today emerged by the middle fifty years of the 19th century (1825–1875). Thus, the characteristics of our modern patent system reflect less the influence of the Framers or of the 18th century than they do the influence of the early to middle of the 19th century.

After establishing our 19th century patent system in Part I, Part II describes the consequences that our 19th century patent system has for present policy debates over patent law. A brief conclusion follows.