Rector Stephen Neill told CBS News that antique records in a parishioner's basement show that the Illinois senator's great, great, great, great grandfather may have been Joseph Kearney, a shoemaker whose shop once stood on a now-vacant field.

"We've got records going back to 1799," Neill told CBS. "It may well be that this may become a major tourist attraction depending on the results of the presidential election next year. So watch this space."

There would be a lesson to be learned if the first black U.S. president had Irish roots, Neill said.

"It's not the first thing you think, is it, when you see him? And that's another thing that's taken people aback, makes you realize how related we all are," Neill said.