The City of Madison is the seat of Dane County, Wisconsin. Within Dane County, approximately 5,600 dairy farms produce more than 600,000,000 pounds of raw milk a year. Besides the milk that’s supplied to Madison, milk produced in the county is sold in Chicago and other surrounding areas, and the remainder is used to make cheese, butter, and other dairy products. The City of Madison had a local ordinance regulating the sale of milk and dairy products within the city. The ordinance prohibited the sale of any pasteurized that wasn’t processed and bottled at an approved pasteurization plant within a 5 mile radius of the central square of Madison.

Dean Milk Co. purchased milk from approximately 950 farms in northern Illinois and southern Wisconsin, none of which were within 25 miles of Madison. Dean Milk’s pasteurization plants were located approximately 65- 85 miles from Madison. At these plants, Dean Milk’s products were processed and inspected by Chicago public health officials and labeled “Grade A” under the Chicago ordinance adopting the rating standards recommended by the U.S. Public Health Service. Because its plants were further than five miles away, the City of Madison denied its license to sell its products in the city.