McGeachie (mag eacaro), MacGaugh (mag eacada), MacGeagh (mag eacada). McCaughan an Anglicized form of the Old Gaelic MacEachain, son of Eachain. An Ulster surname, recorded in the Counties of Antrim, Down, Londonderry and Tyrone. Some families of Mc Caughen changed their name to MacCaughey, itself an Anglicized form of the Ulster name Mac Eachaidh, son of the Horseman or Horse Lord. The Scots names MacGeachie and MacGeachy are also derived from Mag Eochaidh. McGachy, McGeachy. An anglicized version of the Gaelic 'Mac Eochaidh'. A surname in both Ulster and Scotland. William McGaheye settled in York, Virginia, in 1653, and Alexander McGeachy,
Mac and Mc together in print two publications on filing rules, one covering that "word-by-word" convention, and another prepared in 1980 that is "letter-by-letter". A 1998 book attributes the changes to the rules to computer informatics, and notes the Mac/Mc change as its first example. 1982's "Scottish Roots", a guide for family history researchers, warns that older Scottish records do not in fact follow this convention, unlike contemporary telephone directories. A 2001 book of "New York Times" theatre reviews sorts Mc names as if spelled Mac. A 2002 official document for the State of Vermont recommends explicitly no special treatment for Mac and Mc.