Duvall served in the United States Army for a brief period shortly after the Korean War (from August 19, 1953, to August 20, 1954) leaving the Army as private first class [REF].
In the winter of 1955, Duvall began studies at the Neighborhood Playhouse School of the Theatre in New York City,[REF] under Sanford Meisner, on the G.I. Bill.