middle atlantic states Commonwealth of Pennsylvania A state located in the Northeastern and Middle Atlantic regions of the United States. The state borders Delaware and Maryland to the south, West Virginia to the southwest, Ohio to the west, New York and Canada to the north, and New Jersey to the east. LanguaL curation note: US FDA 1995 Code: US42 pennsylvania Commonwealth of Pennsylvania A state located in the Northeastern and Middle Atlantic regions of the United States. The state borders Delaware and Maryland to the south, West Virginia to the southwest, Ohio to the west, New York and Canada to the north, and New Jersey to the east. LanguaL curation note: US FDA 1995 Code: US42 pennsylvania