Franklin acknowledged the receipt of the Law of Nations and he wrote a very nice thank you note. I don’t see the connection.
How about someone who signed both the Declaration and the Constitution and was appointed to an Associate Justice in the Pennsylvania District Court by President Washington;
Having given you this general idea and description of the law of nations; need I expatiate on its dignity and importance? The law of nations is the law of sovereigns. In free states, such as ours, the sovereign or supreme power resides in the people. In free states, therefore, such as ours, the law of nations is the law of the people. Let us again beware of being misled by an ambiguity, sometimes, such is the structure of language, unavoidable. When I say that, in free states, the law of nations is the law of the people; I mean not that it is a law made by the people, or by virtue of their delegated authority; as, in free states, all municipal laws are. But when I say that, in free states, the law of nations is the law of the people; I mean that, as the law of nature, in other words, as the will of nature's God, it is indispensably binding upon the people, in whom the sovereign power resides; and who are, consequently, under the most sacred obligations to exercise that power, or to delegate it to such as will exercise it, in a manner agreeable to those rules and maxims, which the law of nature prescribes to every state, for the happiness of each, and for the happiness of all.
Of the Law of Nations, James Wilson, Lectures on Law
Or a man who was a Virginia Distinct Supreme Court Justice appointed by President Madison;
Of the Unwritten, or Common Law of England; And Its Introduction into, and Authority Within the United American States
....And because this principle was supposed not to have been expressed with sufficient precision, and certainty, an amendatory article was proposed, adopted, and ratified; whereby it is expressly declared, that, "the powers not delegated to the United States by the constitution, nor prohibited by it to the states, are reserved to the states respectively, or to the people." This article is, indeed, nothing more than an express recognition of the law of nations; for Vattel informs us, "that several sovereign, and independent states may unite themselves together by a perpetual confederacy, without each in particular ceasing to be a perfect state.
George Tucker
Which would be Vattel's Law of Nations - Book I,Chap 1, § 10. Of states forming a federal republic
Finally, several sovereign and independent states may unite themselves together by a perpetual confederacy, without ceasing to be, each individually, a perfect state. They will together constitute a federal republic: their joint deliberations will not impair the sovereignty of each member, though they may, in certain respects, put some restraint on the exercise of it, in virtue of voluntary engagements. A person does not cease to be free and independent, when he is obliged to fulfill engagements which he has voluntarily contracted.
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Tucker repeated Vattel almost verbatim, but if you still aren't convinced, here's the U.S. Congressional Documents and Debates [1774-1875] at the Library of Congress search page.
A search for the exact phrase "law of nations" brings up about 99 results, so knock yourself out.