https://twitter.com/GenFlynn/status/1326301903240781831
https://www.pa.gov/guides/state-symbols/#:~:text=The%20Keystone%20State,the%20other%20stones%20in%20place.
https://www.netstate.com/states/intro/pa_intro.htm
https://statesymbolsusa.org/symbol-official-item/pennsylvania/state-nickname/keystone-state
Pennsylvania’s essential role in the founding of the United States earned it the nickname, the “Keystone State.” The term “keystone” comes from architecture and refers to the central, wedge-shaped stone in an arch, which holds all the other stones in place. During the early days of our nation, Pennsylvania held a key position geographically, economically, and politically. Today the keystone is a popular symbol of Pennsylvania — it’s even used as an official symbol of Pennsylvania state government. Each Pennsylvania state agency has its own variation of the keystone as its logo.
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.
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
Keystone State
Known as the “Keystone State” for its geographical centrality to the 13 original colonies, Pennsylvania has played a significant role in US history. Independence Hall in Philadelphia is the site where George Washington became commander in chief of the Continental Army in 1775.
It’s also where the Declaration of Independence was adopted the following year, the US flag was designed and where the founders spent the summer crafting and then adopting the US constitution in 1787. Philadelphia was the temporary capital of the US between 1790 and 1800 while Washington DC was being built.
Pennsylvania’s nickname was reportedly used in a toast during the victory speech when the Republican presidential candidate, Thomas Jefferson, defeated his democratic rival. He referred to the state as the “keystone of the federal union” in 1802. A newspaper stated that Pennsylvania was a “keystone in the democratic arch” in 1803. Even in modern times, Pennsylvania is believed to have an impact on the politics of the United States by many people.