We seem to have an O'NEIL married to a Terrance/Terrence McGahn/Gahan/ McGaughran--those are the listings we see in the census in Brooklyn, New York, USA. Can anyone tell me anything about the pronunciation of that name or any reasons why there might have such confusion about the name and how to write it? Keeping in mind that the person giving the census information might not have been a champion speller and the census taker wrote down what he heard....