Policymakers in the United States have long been perplexed by how to deal with substance abuse. As attitudes shifted in the 19th century toward viewing substance abuse as a medical problem akin to insanity rather than as a moral failing, greater emphasis was given to the potential for treatment. Thus, by the middle of the 19th century, states began developing substance abuse commitment codes and institutions to which substance abusers could be committed. Public ambivalence over whether substance abusers should be seen as having an illness or a weakness of will, however, was reflected in the lack of sustained support for these efforts, in contrast to support accorded systems for commitment of the mentally ill. Contemporary policymakers are faced with the same ambivalence, as they struggle with the extent to which substance abusers ought to be subjected to involuntary treatment. The legacy of the early years of substance abuse commitment lives on.