"Friends Hospital was the first private, exclusively mental hospital in the United States, and is the oldest continuing such institution. The humane treatment of the mentally ill was first successfully established in this country in 1817 by Quakers at Friends Hospital, and that model was copied by many other mental facilities throughout America.
The many surviving historic buildings at Friends Hospital are sited on a large campus located off busy Roosevelt Boulevard just below Oxford Circle that represent a rural oasis in otherwise urban Northeast Philadelphia. Extensive historical landscaping, including renowned azalea gardens (open to the public), are also included in the "National Historic Landmark" designation.
- from Libertynet.org