Final answer:
The first Pennsylvanian elected to the U.S. Congress after the Constitution was ratified is not specified, but James Wilson was a key figure from Pennsylvania during the founding of the United States, serving in the Continental Congress and contributing to the drafting of the Constitution.
Step-by-step explanation:
The first Pennsylvanian elected to the U.S. Congress after the Constitution was ratified would be someone from the initial group of representatives when the federal government started operating under this new system in 1789. However, identifying this individual can be somewhat tricky since the first congressional elections varied by state and exact historical records can be challenging to pin down. It's important to note that James Wilson was a significant figure from Pennsylvania during the founding of the United States; he served as a representative to the Continental Congress, contributed to the drafting of the Constitution, and was later appointed as a Justice of the Supreme Court. Additionally, figures like Joseph Galloway and John Dickinson were prominent Pennsylvania representatives to the Continental Congress before the formation of the U.S. Congress under the Constitution.