 After his ambassadorship, Mansfield served for a time as a senior adviser on East Asian affairs to Goldman Sachs, the Wall Street investment banking firm.Mansfield was born in the Brooklyn borough of New York City, the son of Patrick J. Mansfield and Josephine (née O'Brien) Mansfield, who were both Irish Catholic immigrants.His mother died from pneumonia in 1906, and his father subsequently sent Michael and his two sisters to live with an aunt and uncle in Great Falls, Montana.