Reminder anons
Pennsylvania's nickname is "The Keystone State"
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."
https://statesymbolsusa.org/symbol-official-item/pennsylvania/state-nickname/keystone-state