For those who for some reason may not have heard of it, Cullybackey is a small village in County Antrim, 30 miles (50 km) from Belfast, close to the larger town of Ballymena. It is regarded as, for good or ill, the heartland of rural Ulster Unionist culture, possibly because its population is roughly 97% Protestant to 1% Catholic. Not exactly isolated - nowhere in Northern Ireland is, these days - it is nonetheless not really at the throbbing heart of modernity, or a place that one automatically thinks of as associated with political culture.
So why is it important in American constitutional theory? The local tourism website has the crucial clue: "Arthur Cottage, one of Cullybackey’s most popular tourist attractions, lies just outside the town and is the ancestral home of Chester Alan Arthur, the 21st President of the United States." We will pass ruthlessly over any speculation about Cullybackey's other popular tourist attractions, and cut to the chase. The Rev William Arthur was born in Cullybackey in 1796. He emigrated to Canada in 1818 or 1819, married a couple of years later, and his fifth child, the future President, was born in 1829.
It seems that the Rev William Arthur did not become a naturalised citizen until 1843, which according to a couple of the Birther sites (here and here) means that his son was not a "natural born citizen" of the United States. I confess I do not see the logic of this argument; nobody contests Arthur's mother's US citizenship, and it seems a perverse reading of things that aren't in the constitution to say that his potential dual nationality due to his father's British citizenship should block his claim to lifelong American identity.
It seems that Arthur's eligibility was in fact raised during the 1880 election campaign when he ran and won the Vice-Presidency (and then succeeded as President a few months later when Garfield was assassinated). But the Birthers of the 1880s looked in the wrong place: Arthur Hinman, author of a pamphlet called "How a British Subject Became President", alleged that Chester Arthur had been born in Canada or Ireland, and therefore could not be considered a "natural born citizen". As with rumours of Obama's birth elsewhere than Honolulu, it was not difficult to prove that Arthur had been born in Vermont. The question of his father's citizenship issue remained unexplored. (Arthur, an ill man already, died a few months after his unexpected Presidential term ended in 1885. Most of his personal papers were destroyed.)
I doubt very much that I will bother to explore Cullybackey and its popular tourist attractions, but it gladdens my heart to know that a corner of my own homeland is providing yet more confusion to the Birther debates.