I’m sure they teach the trivium and quadrivium as well.
The boarding schools on this list are highly selective schools with many more applicants than places for students. The acceptance rates are 25% or less. The schools are listed in alphabetical order. I have made no attempt to rank these schools as each one is unique. You need to assess schools on the basis of how they fit your requirements. The best school is always the school which fits best.
via Top Boarding Schools – Top Boarding Schools in the U.S..