This name, chiefly found in the Scottish counties of Ayrshire, Dumfriesshire, and Galloway, is an anglicized from of the Gaelic Mac Cearrach. The Gaelic prefix "mac" means "son of" plus the personal byname Cearrach, a gamester. An alternate derivation suggested by P. Woulfe in his book, "Sloinnte Gaedheal is Gall" (Gaelic and British Surnames), is the Olde Gaelic patronymic Mac Ciothruadha, from "cioth", a shower or fall, plus "ruadha", red, and originally given as a nickname to one with a luxuriant growth of auburn hair. The surname is particularly well recorded in Ayrshire church registers from the late 17th Century, (see below). On January 23rd 1705 Robert McKerrow and Agnas Johnstown were married in Auchinleck and on March 5th 1770 Robert McKerrow an infant was christened in New Cumnock. On November 13th 1866 Margaret McKerrow and John Carruthers were married in Woodam, Dumfriesshire. The first recorded spelling of the family name is shown to be that of Margaret McKerrow, daughter of George McKerrow, which was dated February 5th 1698, christened in Auchinleck, Ayrshire, during the reign of King William III, "William of Orange and England", 1689 - 1702. Surnames became necessary when governments introduced personal taxation. In England this was known as Poll Tax. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.