The makers of public health policy face enormous challenges in the twenty-first century. In the past, their field has been imprecisely defined, deeply conflicted, poorly organized, and constantly changing. Lines of responsibility within the field are blurred at best, and groups with similar goals sometimes find themselves at cross-purposes. In the United States, state and local agencies interact with each other, with federal programs, and with powerful private interests. Many decisions that profoundly affect the health of the public are made for reasons largely unrelated to public health per se. Since the human and financial stakes involved in public health policies are immense, these challenges are, to say the least, serious issues. Underlying this volume is the belief that historical analyses and international perspectives can help policymakers understand, and hopefully begin to address, some of those old challenges in new ways.