Roots of the Well Known
  President Obama retraced some of his lesser-known ancestral roots to a village in Ireland. One of the president's maternal great-great-great-grandfathers was a shoemaker who immigrated to the United States during the height of a crisis in his homeland. Crowds packed the streets to hear Obama speak as he kicked off a four-nation tour of Europe. 

  Adolf Hitler
Adolf Hitler had some interesting finds in his family tree, according to DNA research. The revelation underscores the surprises many people often uncover when researching their genealogy. See what you can dig up about your own family.
  Lionel Richie
When Lionel Richie retraced his roots, he had a little help from a certain TV show. The legendary musician  has ties to an old civil rights organization dating back to 1897 through his great-grandfather. Learn interesting facts about other famous family trees.
  Vanessa Williams
The award-winning actress and former beauty queen has roots in the Tennessee legislature, where her great-great-grandfather served.
  Tim McGraw
This country star found out in his teens that his biological father was this professional baseball player. He's also got ties to this former president, since an ancestor was actually mentioned in one of the former president's journals.
 Emmitt Smith
Football great Emmitt Smith, who also happened to win this show, was able to trace his roots all the way to this West African country, whence his ancestors were brought to America as slaves.
 Alex Haley
His 1976 historical novel "Roots" and subsequent miniseries ignited genealogical interest, especially among African-Americans. Haley's research revealed that his ancestors were slaves from this country. They landed in this Maryland town, which has a statue in honor of Haley telling the story of his family tree.
 Sarah Palin
The Rev. John Lothrop, who came from England in 1634 and founded a New England town, is an ancestor of both Palin and the former president who expanded social services. The ex-Alaska governor is also a distant cousin of this late English princess.
  President Barack Obama
Born in Hawaii, the commander in chief is the son of Barack Obama Sr.a Kenyan, and Ann Dunham  a Kansan. On his maternal side, President Obama is related to his predecessor, a British prime minister and a handsome A-list actor.
  Tom Hanks
Hank's family tree's maternal branch includes 1800s immigrants from a southwestern European country; the paternal branch includes a great American president. Via his stepmom, the California-born actor has Chinese-American siblings.
  Sarah Jessica Parker
Sarah Jessica Parker originally thought her ancestors were German. But she got a surprise in the family tree. Parker's people are English, and her 10th great-grandmother was accused of wicked deeds.
 Eva Longoria
"He's Mexican?" jokes the Tejana actress on learning that she and this Chinese-American cellist share an ancestor. Longoria made the discovery on Henry Louis Gates Jr.'s genealogy series.
  Robert Pattinson
London native Pattinson  star of a certain vampire movie franchise, is a distant relative of the real-life count who inspired an influential Bram Stoker novel. On a less-gothic note, the actor is also a distant cousin of two British princes.
 Tina Turner
On "African American Lives," Turner explores her multiracial heritage. Her great-great-grandfather was an African-American sharecropper and minister; she also has European DNA and blood from these tribes.
  Dwayne 'The Rock' Johnson
Although not born in Hawaii, the wrestler-turned-actor  is of Pacific islander ancestry, specifically here, on his mother's side. Johnson's African-Canadian father, also a wrestling champ, is from a province with a rich black heritage.
  Soledad O'Brien
The CNN reporter's full name, María de la Soledad Teresa O'Brien, offers clues to her heritage. She was born in New York to an African-American mom from this island. Her dad? He's of Irish descent and an emigrant from Toowoomba in this country.
 Hillary Rodham Clinton
The secretary of state has an exciting family tree, including:

 Madonna
 an Oscar-winning actress
 a Canadian diva
 the author of "On the Road"
the singer of "Ironic"