I am trying to trace the McClellan clan of Londonderry and county Donegal, Ireland, whose earliest ancestor I can find is Carey McClellan who died in 1851,Londonderry, born about 1790. His middle name may have been Middleton, as it seems the Carey McCs had/still have that middle name. He was married to Elizabeth Dysart and had 2 sons - Rev. Thomas and William who lived at Greencastle, Moville in co. Donegal. I know Thomas had 5 children (Carey, Mary Anne, Elizabeth, William, John - with William moving to Australia), and William having at least one, Elizabeth. If anyone is aware of earlier ancestors, in particular, and/or the detail on later lines it will be appreciated if you can advise. Thanks.