This is a surname of Gaelic origins which is recorded in an astonishing number different spellings. In so far as there is a 'correct' one it is generally accepted to be MacColum, although no doubt holders of the spellings MacColum, Macallam, MacColm, MacCollom, McCalum, McCallum, McCollum, McColum, McColm, Colum, and many, many, others, may disagree. The original spelling was 'Mac Coluim' or 'Mac giolla Choluim' both of which have essentially the same meaning of the 'descendant of Coluim'. The famous Irish etymologist Woulfe claimed that the name derived from 'colum' meaning 'dove', and gave examples such as Mac giolla Choluim, MacGillacolm, and MacElholm, all forms recorded before circa 1550, and now totally obsolete. In so far as the modern names forms have an epi-centre it is probably County Longford, although as MacColum it is generally regarded as an Ulster surname, and as such was recorded there in Petty's census of 1659. 'Nickname surnames' were quite common in Ireland, therefore the surname may derive from 'dove', but in a transferred sense as in 'a man of peace', a prophet . Early examples of the surname recording include Alexander McCollum who married Alice Warren at St Munchin's Church, Limerick, on May 4th 1760, and Catharine McCullum christened at Clones, County Monaghan, on May 1st 1797. Throughout the centuries, surnames in every country have continued to "develop" often leading to astonishing variants of the original spelling.