One’s view of the patent system depends on what perspective is taken. A narrow focus on the operational level of doctrinal implementation of patent law reveals significant instability and fluctuation in the patent system. A broader focus on the foundational and systemic characteristics of the patent system reveals such substantial stability for so long that the American patent system reasonably can be described as a 19th century patent system. And an even broader focus on the entire history of the American patent system reveals that this stability was only achieved after a period of significant change, diversity, and experimentation in the first few decades of the patent system. The result is a patent system disconnected in significant ways from the modern legal system but one that could be justified on the basis of stability, resilience, and the assumed wisdom of long-standing practice. At the same time, however, mistaking this long-standing practice and potential policy desirability for necessary, inherent, or mandatory features overlooks the instability, change, and diversity in the early decades of the American patent system.