What law should be referenced regarding when and how a natural person becomes a juridical person in the US?
According to Wikipedia:
While human beings acquire legal personhood when they are born, juridical persons do so when they are incorporated in accordance with law.
How does this incorporation tie into citizenship and in what ways is the contract legally binding under commercial or common law?
Natural persons are not and cannot become juridical persons. Juridical persons are entities that are not natural persons, but which it's necessary or convenient to treat in many respects as though they were natural persons. The categories are mutually exclusive. There is no "contract" involved in citizenship from a legal standpoint (there's a concept of a "social contract," but that's a philosophical justification for government and not an actual legally binding agreement with specific terms); citizenship is not subject to commercial law in any way. Incorporation has nothing whatsoever to do with citizenship; a natural person is not incorporated, and is a citizen as a natural person. That citizenship is the ordinary notion of citizenship.
The question seems to rely on a misunderstanding of the nature of citizenship, as cpast has already pointed out. But, bearing that in mind, the question you really seem to be asking is, is there some way for a natural-born citizen of the United States to keep living in the United States, but "opt out" of the jurisdiction of the United States government.
The answer is no.
This kind of shell game of "natural persons," "juridical persons," "incorporated legal persons," and so on, is used frequently by people who want to convince you that they have found a magic loophole in the legal system that means that you are not subject to government control unless you affirmatively take certain steps, or that you can escape the jurisdiction of the country you live in by taking certain steps. The term usually used is "sovereign citizen."
Let me be perfectly clear: all of these theories are absolutely, positively, 100% wrong. None of them make a damn bit of sense to any serious student of the law--and more importantly, none of them have ever been used successfully in any U.S. court.
A person of legal age is entirely free to decide not to be subject to the jurisdiction of the United States. You do this by leaving the United States, renouncing your citizenship, and then not coming into, or doing business with, the United States. Otherwise, if you remain in the country, taking advantage of the public infrastructure and services, you are subject to U.S. jurisdiction (as the citizen of any country would be).
