As a young lawyer in 1949, he participated in the Hiss-Chambers Case, and later became a leading expert in international arbitration in a career spent at the law firm of Debevoise & Plimpton.

[1][2] He won a national scholarship to Yale University and graduated summa cum laude.

He then studied at Harvard Law School, where he graduated magna cum laude in February 1946.

[4] In 1988, von Mehren married Susan Heller Anderson, a writer and reporter for the New York Times.

[1][2][3] He was an avid sailor and raced on Martha's Vineyard, where he owned a home in Chilmark bought from James Cagney in 1957.