People seeking to trace ancestral links between Ulster Scots and North American descendants are now using DNA testing to aid their search.
One speaker used DNA to make a connection with US John McCain
An international symposium taking place in County Tyrone is focusing on how families can trace relatives going back hundreds of years.
One of the speakers has used DNA testing to make a connection with US Presidential nominee, Republican John McCain.
Genealogist Barry McCain also used the scientific method to connect many McCain families in Ireland and America.
Symposium organisers said it would show the significance of emigrants on shaping modern North American society.
Dr Brian Lambkin, director of the Centre for Migration Studies at the Ulster American Folk Park, said: "We are hosting a series of lectures by eminent and widely respected researchers, academics and historians.
"They will reveal fascinating insights into a range of subjects such as the links between Ramelton in Donegal with the Caribbean, the attitude of Presbyterians to slavery in the post-civil war southern states, the roots of Patsy Cline's brilliant country music career and even a Gaeltacht in New Brunswick."
The keynote speaker will be Professor David Cannadine, Director of the Institute of Historical Research in the University of London.