We know they were, because they mentioned Naturalization in Article I Section 8 Clause 4.
Naturalized citizens become We The People after they are naturalized, and then once naturalized, but not before, their posterity are citizen children.
If resident aliens have children here before they become naturalized, then those children's (who are dual citizens who claim birthright in the United States but also inherit the citizenship of their parents) children will become natural born citizens, but they themselves will not.
That's why I think that the SCOTUS was wrong in Minor v. Happersett when they said they had to look elsewhere for the definition of "natural born citizen." That definition is right there in the Preamble as I've just shown.
The Preamble sets the context of the rest of the Constitution, namely to preserve the country for its citizens and their citizen children.
-PJ
You are entitled to and I respect your opinion. We can all talk about this until we are blue in the face but the fact is it is what it is. The framers were probably concerned by the Jay letter of a usurper taking control of the presidency. Perhaps that is why the committee of eleven changed “citizen” to “natural born citizen.” They certainly didn’t elaborate on it and it remains a mystery.
What isn’t a mystery to me is, and I would bet every dime I own on this, an anchor baby will one day run for President, and there will not be a court in the land that will stop him. I don’t like it but there it is unless the Supreme Court takes a stand and actually defines NBC.