Yes, the research that was done was from the Library of Congress. It does make a great case that the term NBC comes from Vattel. That would mean Obama is not eligible. It would require SCOTUS for offical decree.
It's definition has been there for centuries, it's only when someone gets their panties in a wad that they have to go running to the SCOTUS on something like this. Just because BJ didn't know the meaning of “is” was no cause to run it up the flagpole to the Supremes. You want something more recent than the founding fathers? How about going by the definition Obama agreed upon just last year? When McCain's citizenship was questioned a Senate committee was formed to resolve the problem. That committee consisted of 5 RATS (inculding Obama and Hillary), 1 Republican, and Chertoff (former federal judge and head of Homeland Security) was asked to weigh in. They agreed down through the years and by “common sense” “natural born” was eligibility through both parents (the plural) being US citizens.
http://leahy.senate.gov/press/200804/041008c.html