The primary claim of this essay is that historical fluency is required for effective work in crafting legal and policy interventions as a part of public health emergency preparedness and response (PHEPR). At a broad level, public health law is explicitly recognized as a key systems-level component of PHEPR practice.11 This essay therefore focuses on the extent to which historical fluency is necessary or at least useful to all aspects of PHEPR that draw on or deploy legal and policy mechanisms (e.g., design, planning, implementation, dissemination, monitoring and evaluation, etc.). The essay collectively refers to these legal and policy mechanisms as epidemic law and policy response (ELAPR). Part I explains the concept of historical fluency. Part II explores the foundations of public health law both as a way of highlighting key structural features of ELAPR and in supporting the claim that historical fluency is critical for ELAPR. Part III applies the previous arguments to a specific case study to highlight the promise and power of historical fluency – the outbreak of bubonic plague in San Francisco in 1900. Tracking this essay’s pragmatic focus, part IV offers several recommendations for how specifically historical fluency in public health law and ethics can be operationalized in PHEPR practice and policy. Part V summarizes and concludes.