James O'Brien (U.S. Congressman)

O'Brien directly contributed to the downfall of the Tweed ring of Tammany Hall by providing city financial accounts to the New York Times in 1871.

James Watson, who was a county auditor in Comptroller Dick Connolly's office and who also held and recorded the ring's books, died a week after his head was smashed by a horse in a sleigh accident on January 21, 1871.

Although Tweed guarded Watson's estate in the week prior to Watson's death, and although another ring member attempted to destroy Watson's records, a replacement auditor, Matthew O'Rourke, associated with the former sheriff James O'Brien, provided city financial accounts to O'Brien, who then forwarded the accounts to the New York Times.

[1] O'Brien served in the New York State Senate in 1872 and 1873, during which time he founded the Apollo Hall Democracy.

John Kelly, the new Tammany Hall boss, attended the trial and Croker was freed after the jury was undecided.