In October, 1905, he became fourth vice-president; in March, 1909, third vice-president; and in March, 1911, second vice-president of the company. Mr, Thayer was a director of the Pennsylvania Railroad and its more important controlled lines east of Pittsburgh, including the Long Island and the New York Connecting; he was director and president of the Eric & Western Transport union Company, and was a director of the Norfolk & Western and the Lehigh & Hudson River. He was a member of a large number of clubs and organizations, including the Philadelphia Club, the Union League and the Union Club of New York, the Metropolitan Club of Washington. D. C, the Railroad Club of New York, and the Chamber of Commerce of the state of New York.