The Canal Ring referred to the group of corrupt contractors and their political supporters who conspired shortly after the American Civil War to defraud the State of New York by overcharging for repairs and improvement of the state's canal system. It defied an "investigation" in 1868 and for years was powerful enough to prevent interference and to defeat unfriendly candidates for office.
The group was finally broken up by Governor Samuel J. Tilden in 1874. Tilden employed a skilled engineer to examine their work and then surprised the legislature by a wholly unexpected special message setting forth in detail the fraudulent methods of the ring. This served as a direct appeal to the people, and so aroused public opinion that the legislature was forced to authorize the governor to appoint a canal commission. The reports of this commission resulted in a marked diminution in the appropriation for canals and the indictment of several officials for defrauding the State.