John Caspar Dreier

John Caspar Dreier (December 27, 1906 – March 10, 1994) was a U.S. diplomat.

He served as United States Ambassador to the Organization of American States between 1951 and 1960. He then taught for a number of years at the School of Advanced International Studies (part of Johns Hopkins University in Washington, D.C.). After retirement he played an active role as a teacher and trustee of the College of the Atlantic in Bar Harbor, Maine.

Publications