This article is one of the best I've read on the weird, " Idiotic and insulting" liquor laws some states have. In Pennsylvania (and Maryland, Virginia, Kansas etc), "The state monopolizes sales of hard liquor and wine and limits the hows and wheres of beer buying too, all in the name of saving citizens from themselves while piling up tax revenues for those same residents."
State liquor stores, stores which only sell wine and beer and are usually close to grocery stores which are not allowed to sell these things. Basically the states that make getting these products difficult are only looking at it as a revenue stream, but as the article points out, these states would probably make more money if they got out of the liquor sales business.
Here's a map of states which allow all alcohol products in grocery stores. We're pretty lucky here in Illinois and Missouri because if you have company coming and want some wine or anything else you can just drop it in the shopping cart along with the groceries. Not so in other places which require a trip to an entirely different place.
This is on my mind right now because we're going out to Maryland and the DC area later this week and I know what a pain it is to pick up a bottle of wine along with fixings for dinner.