After Harvard, Simmonds joined the
Texas and Pacific Railway Company in New York City. In 1930, he joined the
Bank of New York and after subsequent stints as assistant treasurer, assistant vice president and vice president, he was elected to succeed
John C. Traphagen as
President of the Bank of New York in 1948. In 1957, he became chief executive officer and chairman of the bank, serving until his death in 1963. In 1960 and 1961, he was president of the New York State Bankers Association. Simmonds also served as a trustee, or director, of the
Greenwich Savings Bank, the North American Reassurance Company, the
Celotex Corporation, the American Casualty Insurance Company, North American Reinsurance Corporation, the
Borden Company, the Valley Forge Life Insurance Company, and the Valley Forge Insurance Company. ==Personal life==