In Minnesota where I live, citizens can't buy alcohol on sundays (I'm not sure about the status of the law in other states). Apparently this is known as a Blue Law. It was originally enacted a puritan law, and was on the books next other laws that prohibited other businesses from being operated on Sundays. The laws were apparently enacted also to encourage church attendance. Nowadays, the laws are
legal
because they "promote the general welfare."
The law seems ridiculous.
(source: http://wcco.com/goodquestion/Good.Question.alcohol.2.372465.html)