Pennsylvania has been known as the Keystone State since 1802, based in part on its central location among the original Thirteen Colonies, and in part on the number of important American documents signed in the state, including the Declaration of Independence.

Many establishments outside of Philadelphia refer to the cheesesteak sandwich as a "Philly cheesesteak".

Affectionately known as the "City of Bridges", Pittsburgh boasts 446 bridges--more than any other city in the world, including Venice, Italy.

Pennsylvania founder William Penn proposed and led a mass immigration of English Quakers fleeing religious persecution. In colonial times, Pennsylvania was known officially as the Quaker Province, in recognition of Penn's First Frame of Government constitution that guaranteed liberty of conscience.

The eastern hemlock grows well in shade and is very long lived, with the oldest recorded specimen, found in Tionesta, Pennsylvania, being at least 554 years old.

After George Washington's defeat at the Battle of Brandywine on September 11, 1777, the revolutionary capital of Philadelphia was defenseless and prepared for British attack. The Supreme Executive Council of the Commonwealth of Pennsylvania ordered that eleven bells, including the Liberty Bell, be removed from the city to prevent the British from melting them down for cannonballs. The bells were hidden in the basement of the Zion Reformed Church in what is now Allentown.

The Battle of Gettysburg was fought July 1-3, 1863, in and around the town of Gettysburg, Pennsylvania. Union Maj. Gen. George Meade's Army of the Potomac defeated attacks by Confederate Gen. Robert E. Lee's Army of Northern Virginia, halting Lee's invasion of the North. The battle involved the largest number of casualties of the entire war and is often described as the war's turning point.

During the American Revolution, Lancaster was the capital of the United States for one day, on September 27, 1777, after the Continental Congress fled Philadelphia, which had been captured by the British. The revolutionary government then moved still farther away to York, Pennsylvania.

Pennsylvania is misspelled "Pensylvania" on both the Liberty Bell and parts of the Constitution. This spelling was one of several acceptable spellings of the name at that time.

Philadelphia played an instrumental role in the American Revolution as a meeting place for the Founding Fathers of the United States, who signed the Declaration of Independence in 1776 at the Second Continental Congress, and the Constitution at the Philadelphia Convention of 1787.