My great-grandfather, John O'Hara (or "Grandpa JJ," as I knew him), was born in Brooklyn in the late 1896, the child of Irish immigrants John O'Hara and Mary King. When he was a boy, his family returned to Ireland, where they lived in Castlebar, Co. Mayo, for a few years. His father ran a pub, but they sold it and returned to Ireland in 1902, when he was 6 years old. While the family was in Ireland, they were always recorded under the name "O'Hora," and all of the records of our forebears in the area are of O'Horas.
Despite being a Brooklyn native, John entered school with an Irish brogue because of the years he had spent there. According to stories my dad told me, the other kids used to tease him* by making him say "forty-four," because he pronounced it "farty-far," which sounds like "fart."
When my dad was a kid, and his grandfather was trying to teach him to speak with an Irish brogue, he started him with saying "farty-far" for "forty-four."
The other night, I had an epiphany. When I look at O'Hora, I pronounce it with a long O - the same vowel sound as in "four." My brogue-having O'Hora ancestors would have pronounced their name O'Hahra - with the same vowel sound as in "far." No wonder that as they adjusted to life in America, the American spelling shifted to reflect the way the name was pronounced! I marvel that I never noticed the simplicity of it. I'm not sure I can really claim that my family's name changed at all.
*Something about this doesn't ring true to me. Brooklyn in 1902 would have had a substantial population of kids and/or their parents who spoke with the accents of Ireland and other countries. Would it really invite ridicule from his schoolmates, many of whose parents undoubtedly spoke with a similar brogue?