Official State Nickname of Pennsylvania
Pennsylvania's nickname is "The Keystone State" because it was the middle colony of the original thirteen colonies, and because Pennsylvania has held a key position in the economic, social, and political development of the United States. All State Nicknames
Three of our most treasured documents are associated with Pennsylvania: the Declaration of independence and the United States Constitution (both executed in Philadelphia), and Lincoln's Gettysburg Address.
Pennsylvania's state song mentions the state nickname in the second verse: "Birthplace of a mighty nation, Keystone of the land." A keystone is also featured on the U.S. Mint's Pennsylvania quarter.
What is a Keystone?
The word keystone is from architecture, it describes the central wedge-shaped stone in an arch which holds all the other stones in place.