It isn't that hard to see that he's talking about his signing of the Federal Reserve Act of 1913. "A Great industrial nation is controlled by its system of credit," which would mean he has to be talking about banking and finance to begin with, but banking and finance had been around from the beginning of the nation. Wilson also said, "I have unwittingly ruined my country," which must reference something he did. I see no alternative but the Federal Reserve Act of 1913.