That is the book consulted by the Founding Fathers when they wrote the Constitution.
Correct. Vattel’s contemporaneous legal treatise “The Law of Nations or the Principles of Natural Law” was used by the founders and framers to justify the revolution again the King of England and to write the founding documents. It was the source and original intent meaning, purpose, and understanding of the constitutional term “natural born Citizen”: https://lonang.com/library/reference/vattel-law-of-nations/vatt-119/ For more on that see: https://www.thepostemail.com/2023/04/15/my-translation-of-a-key-sentence-in-emer-de-vattels-1758-treatise-on-natural-law-in-section-212-des-citoyens-et-naturels/ ... and ... http://www.kerchner.com/protectourliberty/The-Who-What-When-Where-Why-and-How-of-NBC-Term-in-Constitution.pdf