The New England Historic Genealogical Society released their genealogy report Tuesday after tracing the family trees of the top three presidential candidates.
Sen. Barack Obama, the daughter of a white woman from Kansas and a black man from Kenya, is related to several presidents across both party lines.
Obama's distant presidential cousins include President George W. Bush and his father, George H.W. Bush, Gerald Ford, Lyndon Johnson, Harry S. Truman and James Madison.
Obama is related to other politicians, such as Vice President Dick Cheney, British Prime Minister Sir Winston Churchill and Civil War General Robert E. Lee.
Sen. Hillary Clinton, who is of French-Canadian descent on her mother's side, is related to singers Madonna, Celine Dion and Alanis Morissette. Clinton's other relatives include author Jack Kerouac and Camilla Parker-Bowles, the wife of Prince Charles of England.
Ironically, Obama is related to Brad Pitt, while rival Clinton is related to Pitt's girlfriend Angelina Jolie. Obama and Pitt are ninth cousins, linked by Edwin Hickman, who died in Virginia in 1769. Clinton and Jolie are also ninth cousins, twice removed, both related to Jean Cusson who died in St. Sulpice, Quebec, in 1718.
Obama and President Bush are 10th cousins, once removed, linked by Samuel Hinkley of Cape Cod, who died in 1662.
Sen. John McCain's ancestry was more difficult to trace because records on his relatives were not as complete as the records for the families of Obama and Clinton, said genealogist Christopher Child. However, it was determined that McCain is the sixth cousin of First Lady Laura Bush.
Founded in 1845, the New England Historic Genealogical Society is the oldest and largest nonprofit genealogical organization in the country.