When Lithgow Osborne was in the middle of his senior year at Harvard University in 1914, Joseph C. Grew snapped him up for an assignment in the United States Embassy in Berlin as a private secretary to Ambassador James W. Gerard.

Osborne was transferred to the American Legation in Havana before President Wilson broke U.S. relations with Germany.

On December 20 the same year Osborne presented his credentials as ambassador to King Haakon VII of Norway (in exile during World War II) in London and served until April 20, 1946.

After taking care of the relationship with Norwegian exiles in London during World War II, Osborne moved to Oslo after the liberation in May 1945.

[1][2][3] For several years after his return from Oslo, Lithgow Osborne was chairman of the board of trustees for the American Scandinavian Foundation.