White 'slave-owner' roots of Michelle Obama revealed Last updated at 4:43 PM on 09th October 2009 In November last year, she stood alongside her husband as he made history by becoming the first African American President of the U.S. But while President Barack Obama's racial heritage has received considerable attention, that of his wife Michelle has remained shrouded in mystery... until now. Genealogists in the U.S. have traced back five generations to a union between an white man and a slave called Melvinia Shields. Melting pot: Dolphus Shields (left), is mixed race great-great-grandfather of U.S. First Lady Michelle Obama The identity of Mrs Obama's great-great-great grandfather is unknown, but it is thought he could have been a plantation owner's son-in-law. It is a family history very similar to the award-winning 1976 Alex Haley novel Roots: The Saga Of An American Family, which went on to become a hugely popular TV series. The line started by Melvinia Shields and the mysterious white man who impregnated her marks the beginning of a family tree which would travel through rural Georgia, Birmingham in Alabama, to Chicago and finally the White House itself. The research, carried out by The New York Times, found that in 1859 Melvinia, Mrs Obama's great-great-great-grandmother, bore her first child when she was 15-years-old in 1859. He was Dolphus Shields, Michelle's great-great grandfather, who stood out in turn of the century America others because of his light skin. History: Barack Obama celebrates with wife Michelle and daughters Sasha, left, and Malia after being elected According to researchers Melvinia was owned David Patterson who ran a plantation in South Carolina. In the estate owner's will, written in 1852, he listed "negro girl Melvinia" in an inventory of his property. Illiterate, she lived with 21 other slaves and was valued at $475, Genealogists Megan Smolenyak,who conducted the research, believes Melvinia was most likely made pregnant by Patterson's son-in-law Henry Shields. At the time Shields was in his late 40s and had four sons. It is also possible that one of the sons, aged from 19 to 24, could have been the father. Historians said Melvinia could have been raped by one of the Shields' family, but the circumstances of the union are unknown. Roots: Mrs Obama (bottom right) with her parents Fraser and Marian Robinson and her brother Craig 'No one should be surprised anymore to hear about the number of rapes and the amount of sexual exploitation that took place under slavery,' said law professor Jason Gillmer. Melvinia went on to have three other children apart from Dolphus and after slavery was abolished she continued working in the fields of a farm in Georgia. Census records uncovered by Smolenyak revealed that Melvinia died in 1938. Her death certificate listed parents names as 'don't know'. Her eldest son Dolphus became one of the first generation of free blacks. He moved to Birmingham, Alabama, where he worked as a carpenter. Dolphus stood out because of his light skin, and was often mistaken for a white man. By 1911 he owned his own carpentry business and his first wife Alice Easley gave birth to two sons. Enlarge One of these, Robert Lee Shields, Mrs Obama's great grandfather, married Annie Lawson in 1906 and worked as a railroad labourer. Their son Purnell married Rebecca Jumper in 1929 and their daughter Marian, who was born in 1937, is Michelle's mother. The First Lady's lineage on her father's side can also be traced back to a slave born on a plantation in Georgetown, South Carolina. Historian Edward Ball said of Mrs Obama: 'She is representative of how we have evolved and who we are. 'We are not separate tribes of Latinos or whites and blacks in America. 'We've all mingled and we have done so for generations.' The full family tree was published for the first time in the New York Times newspaper under the headline 'First Lady's Roots Reveal Twisty Path from Slavery' It said Mrs Obama refused to comment over the family tree because of the personal nature of the subject.