Dean Milk Company v. City of Madison 340 U.S. 349 (1951)
DEAN MILK COMPANY v. CITY OF MADISON 340 U.S. 349 (1951)
A Madison, Wisconsin, city ordinance that prohibited the sale of milk pasteurized at a plant more than five miles outside city limits provided the basis for clarification of the limits on state regulation of commerce. A 6–3Supreme Court invalidated the law as an "undue burden on interstate commerce " because it effectively barred the sale of milk from firms in neighboring Illinois. Justice tom c. clark also found a discrimination against outside producers which could not be sustained as an exercise of the state's police power when "reasonable nondiscriminatory alternatives" were available, as here.