American suffragist, also known as Tennie C. and later Lady Cook. She was best known as one of the first women to open a Wall Street brokerage firm. Her stock market gains financed the publication of her radical feminist newspaper, and she was an advocate of legalized prostitution.
On 5 February 1870, Claflin and her sister Victoria Woodhull formally opened the doors of their business, Woodhull, Claflin & Co., to the public. At the stock and gold exchanges, the news of a brokerage firm operated by women was greeted with a frenzy of speculation. The sisters’ ingenuity won them praise and publicity, earning them the nicknames, The Bewitching Brokers and The Queens of Finance.
During the 1870s she was a flamboyant proponent of women’s rights with her sister. Tennessee ran for the United States Congress in the state of New York. She held the controversial belief that women could serve in the military and was elected Colonel of a “colored” National Guard Regiment.
At twenty-two she had met Cornelius Vanderbilt and they began an affair. The married Vanderbilt died on 4 January 1877, worth $100 million. Tennie and her sister were paid $100,000 by a Vanderbilt heir to make themselves unavailable to testify about Vanderbilt’s involvement in spirit communications.
On 15 October 1885, in England, Tennie married the vastly wealthy widower Sir Francis Cook, Viscount of Monserrate, Portugal, after telling him that the spirit of his dead wife told her she approved. Queen Victoria created a Cook Baronetcy. As the wife of an English baronet, Claflin would thereafter have been correctly styled “Lady Cook, Viscountess of Montserrat.” When Sir Francis died sixteen years later amid rumors that she had murdered him, Tennie inherited $250,000.
She died on 18 January 1923, in England, aged seventy-seven.

Link to Wikipedia biography