Mercer County List. Any help would be greatly appreciated. I know Henry Macom came from Ireland but I have been unable to locate him there. The documented information I have is on Henry Macom (born 1782). He and his wife Anne sailed from Belfast to Baltimore June 1817. He bought a farm in Mercer in 1820 from John Sharp. Sharp bought it from Peter Maury. I have received information which I can not confirm that Henry was born in County Armagh. His father John Macom was born in Armagh about 1750 and was married to Elizabeth Spark. Annes parents were Vance Holmes and Mary. Thanks, Lori Macom .