Pennsylvania

In the United States, Pennsylvania is a state located in the Mid-Atlantic, Northeastern, and Appalachian regions. It is formally known as the Commonwealth of Pennsylvania. Ohio is bordered on the southeast by Delaware, on the south by Maryland, on the southwest by West Virginia, on the western by Ohio, on the northwest by Lake Erie and Ontario, on the northern border by New York, and on the east by New Jersey. The Appalachian Mountains run through the middle of the state, separating it from the other states.

Pennsylvania is the 33rd-largest state in terms of land area and the 5th-most populated state in the United States, according to the most recent official United States Census count in 2020. Of the 50 states, it has the ninth highest density of population. In Pennsylvania, the Delaware Valley, which is concentrated around the state's biggest metropolis Philadelphia (6.25 million people), and Greater Pittsburgh are the two most populated metropolitan regions (2.37 million). Harrisburg is the state capital as well as the state's 15th most populous city. In addition to Lake Erie and the Delaware River, Pennsylvania has 140 miles (225 kilometres) of coastline.

The state is one of the Thirteen original founding states of the United States; it came into being in 1681 as a result of a royal land grant to William Penn, the son of the state's namesake. Part of Pennsylvania (along the Delaware River), together with the present State of Delaware, had earlier been organized as the Colony of New Sweden. It was the second state to ratify the United States Constitution, on December 12, 1787. Independence Hall, where the United States Declaration of Independence and United States Constitution were drafted, is located in Philadelphia, the state's largest city. During the American Civil War, the Battle of Gettysburg was fought in the south central region of the state. Valley Forge near Philadelphia was General Washington's headquarters during the bitter winter of 1777–78.