The importance of public health measures applied to the community at large in reducing rates of illness and death cannot be overemphasized. During the nineteenth century, the isolation of illness was a significant step forward in limiting the spread of disease. In addition, expanding knowledge of bacteriology led to improvements in community cleanliness in the form of water purification and sewage disposal systems. The pasteurization of milk represented significant progress for the safety of this commodity, with related sanitary measures being instituted in the manufacturing, packing, and sale of other foods.

In the 1800s, a series of publications documented adulteration of the food supply and the resulting negative impact on both the nation's economy and public health. In 1850, a landmark public health report by Shattuck documented the decrease in average life expectancy at birth in America's large urban centers and identified the adulteration of food and drugs as a matter of public health concern. The report recommended that local boards of health be established to ''endeavor to prevent the sale and use of unwholesome, spurious, and adulterated articles, dangerous to the public health, designed for food, drink, or medicine'' (Shattuck, 1850). Following that report, boards of health were established by cities, counties, and States throughout the country. State Departments of Agriculture were also established with authority to regulate the manufacture of food products. In 1888, Congress enacted the first broad food and drug legislation for the District of Columbia, which was subsequently strengthened in 1893 (Hate and Brown, 1985).

Following the American Revolution, the nation was governed first under the Articles of Confederation, which permitted the States to regulate activities within their borders. However, the Articles ultimately failed to ensure a cohesive union because each State retained its own sovereign powers, leaving the national government without the authority to govern or resolve either domestic or foreign problems (Teller, 1983).

A compromise made during the Constitutional Convention of 1789 allowed the States to retain their traditional powers, including the "police powers" under which they could act to protect the health and welfare of the public. At the same time, the Convention agreed that laws enacted by the Federal government under its enumerated powers would be supreme, including the laws regulating "commerce ... among the several States"