Kennedy also served as a trustee of the Central Trust Company from 1882 until he died. Kennedy held similar positions with the National Bank of Commerce from 1887 to 1909, the New York Life Insurance Company from 1903 to 1906, the Title Guarantee and Trust Company from 1895 to 1909, and the United States Trust Company of New York from 1896 to 1909. As a result of his varied banking activities, Kennedy became a central figure in the history of American banking and in the New York business community.