The U. S. used to have "blue laws", which prohibited businesses being open on Sunday. I believe it was the case (until somebody posts 25 references saying that it wasn't) that pharmacies - "drug stores" - were generally exempt from these laws, since being able to obtain medicine was a necessity. Because they could stay open on Sunday, they started stocking other items besides drugs/medicines because people found it convenient to be able to shop for these things on a Sunday. As a result, "drug stores" turned into little general stores. Soda fountains/snack bars would be an obvious extention of this trend.

Unless I'm wrong.

Don