Hello,
I am the descendant of an Irishman named James Miller who was in Eastern Tennessee (US) by 1803 when his son John Miller was born. I am unable to locate James Miller before 1803 nor am I able to locate him afterwards. i believe he died before 1820 in South Carolina. His son John Miller married Nancy Mary Wilson, daughter of Joseph Wilson, a farmer and a trader. John and Nancy Mary Wilson Miller are enumerated in the 1830 Monroe County, TN census; he is an attorney, a county and probate judge, with enough cash to purchase property in GA in 1838.
I posted the above history because I thought it might be helpful because I wonder which county in Ireland would be the most likely for Millers to live. Evidently they were educated and had financial resources. Since I have no idea what date he emigrated to the US, I don't know which ship or where he may have departed or entered the US. This is a shot in the dark hoping someone may know where Millers and Wilsons may have lived in N. Ireland.