The New England Historic Genealogical Society said the Democratic president's mother, Stanley Ann Dunham, and Brown's mother, Judith Ann Rugg, are both descendants of Richard Singletary, a Massachusetts man who died in 1687 at the age of 102.
The researchers said Singletary, like his descendants, held public office, serving as a selectman in the Massachusetts towns of Salisbury and Haverhill.
The genealogical society also found family links between Brown and six previous U.S. presidents: George W. Bush, George H. W. Bush, Richard Nixon, Herbert Hoover, Calvin Coolidge and Rutherford Hayes.
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