The Commonwealth of Pennsylvania ( ), often colloquially referred to as PA (its abbreviation) by natives and Northeasterners, is 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.

Pennsylvania has been known as the Keystone State since 1802,PHMC: State Symbols based in part upon its central location among the original Thirteen Colonies forming the United States. It was also a keystone state economically, having both the industry common to the North, making such wares as Conestoga wagons and rifles, and the agriculture common to the South, producing feed, fiber, food, and tobacco.

Another one of Pennsylvania's nicknames is the Quaker State; in colonial times, it was known officially as the Quaker Province, in recognition of Quaker William Penn's First Frame of Government constitution for Pennsylvania that guaranteed liberty of conscience. He knew of the hostility Quakers faced when they opposed religious ritual, taking oaths, violence, war and military service, and what they viewed as ostentatious frippery.

Pennsylvania has of coastline along Lake Erie and of shoreline along the Delaware Estuary. Philadelphia is Pennsylvania's largest city and is home to a major seaport and shipyards on the Delaware River.

Geography

see: List of Pennsylvania counties

The bounds of the state are the Mason-Dixon Line (39° 43' N) in the south, the Delaware River in east, 80° 31' W on the west, and the 42° N parallel on the north, with the exception of a short segment on the western end, where a triangle extends north to Lake Erie. Pennsylvania borders six other states: New York to the north; New Jersey to the east; Delaware and Maryland southeast; West Virginia southwest, and finally Ohio to the west.

It has cities of Philadelphia in the south-east, Pittsburgh in the south-west, Scranton and Wilkes-Barre in the north east, and Erie in the north-west, with state capitol Harrisburg on the Susquehanna River in the central region of the commonwealth.

Climate

Pennsylvania's diverse geography also produces an variety of climates. Straddling two major zones, the southeastern corner of the state has the warmest climate. Greater Philadelphia lies at the southernmost tip of the humid continental climate zone, with some characteristics of the humid subtropical climate that lies in Delaware and Maryland to the south. Moving toward the mountainous interior of the state, the climate becomes markedly colder, the number of cloudy days increases, and winter snowfall amounts are greater. Western areas of the state, particularly cities near Lake Erie, can receive over of snowfall annually, and the entire state receives plentiful rainfall throughout the year.