I suspect we may be related. My great-grandfather, James Robb, emigrated from Co Armagh Parish of Derrynoose near
Crossreagh to Perth County and Logan Township in the very early 1840's. He came with his widowed mother Mary and brothers Alexander, William, John, and Thomas and sister Helen. All, except widow Mary are buried in the Knox Presbterian Cemetery in Mitchell Ontario. I believe a nephew of Mary and cousin of James, John Robb, came with them. I believe he was in the next township over from Logan. Some of his descendants spell their name Rabb. James was married to Elizabeth Rooney.