BEFORE 1938, the only drugs for which prescriptions were needed were certain narcotics specified in the Harrison Anti-Narcotics Act of 1914.1 Any other drug could be obtained by walking into a pharmacy and buying it. If a person wished to see a doctor and get a prescription, he could. But any nonnarcotic drug he could buy with a prescription could also be bought without one, and any prescription could be used as many different times and for as many different people as desired. This state of affairs ended in 1938 when two different categories of nonnarcotic drugs-prescription and over-the-counter-were created. Although the Federal Food, Drug, and Cosmetic Act was passed in 1938, this distinction was not spelled out in that law. In fact, it seems clear that the legislative intent of that law was violated by this distinction. This paper recounts the story of how a new category of nonnarcotic prescription drugs was created in 1938 and how it was finally written into law in 1951. The story is told in three parts. The first part recounts the organizational and legislative history of the 1938 law. The second part shows how the Federal Drug Administration's regulations extended the law to create the distinction between prescription and over-the-counter drugs. The third part describes the subsequent history of this regulation in the Supreme Court and Congress. A final section summarizes the argument.