In addition to all of the above I would like to include The College of William and Mary
The College has been called “the Alma Mater of a Nation” because of its close ties to America’s founding fathers. A 17-year-old George Washington received his surveyor's license through the College and would return as its first American chancellor. Thomas Jefferson received his undergraduate education here, as did presidents John Tyler and James Monroe.
I guess you when say "no one" you didn't mean all these other people....
Interesting to read some of the commentary on Vattel in that document:
"Vattel's definition of a Nation imputes Nationality to a Band of Robbers, a Crew of Pirates, a Caravan of Merchants, or the Crew of a Merchant Ship."
"Vattel confuses his reader by predicating Sovereignty sometimes of the Ruler, and sometimes of the Body Politic itself whose creature the Ruler is..."
"Vattel's idea of the Balance of Trade is exploded as absurd."
"Vattel states this vaguely because he starts wrong."
"Here again Vattel inculcates a loose morality not worthy of him."
It looks like people might have been interested in what Vattel had to say, but that doesn't mean they simply accepted all of it.