Mac Cumhaigh (MacCooey), Art (c.1738–1773), poet, was probably a native of the townland of Mounthill in the parish of Creggan, Co. Armagh, but local tradition also links him with Mahereagh in the parish of Barronstown, near Dundalk, Co. Louth, and he may have lived in the latter place for some time. His parents were small farmers and he had at least one brother, Toirealach, who farmed at Mounthill.
Although Mac Cumhaigh obtained an education, attending a hedge school where his fellow pupils included a future priest, and showed a familiarity with classical and Irish mythology in his writings, he worked as a gardener or an agricultural labourer throughout his life. On one occasion he was obliged to leave Creggan as a result of a quarrel with the parish priest, Fr Terence Quinn. A poem (‘Tá ribíní daite ar gach páiste istír’), in which Mac Cumhaigh criticised the lack of hospitality shown him by the priest's sister and housekeeper, may have exacerbated this dispute, but the principal matter at issue seems to have been the poet's decision to marry his second cousin, Mary Lamb, in the established church because of the expense involved in obtaining a dispensation to marry a close relative in the catholic church. Mac Cumhaigh is believed to have spent part of his time in ‘exile’ at Howth, Co. Dublin, but he returned to Creggan after obtaining the necessary dispensation, and a song in praise of Fr Quinn's sister (‘Tá géag gheal dheasaithe bhéalbhinn bhreasnaí’) may have been composed to mollify his clerical opponent at the same time.
The O'Neills of the Fews, a branch of the O'Neills who were the dominant family in the south Armagh barony until the 1650s, occupy a central position in Mac Cumhaigh's work. Two of his compositions (‘Ar bhruach Dhún Réimhe ar uaigneas lae’ and ‘A aolchloch dhaite bhí i bhfad ag síol Néill gan smúid’) lament the ruined state of Glasdrummond castle, the former seat of the O'Neills, and its condition serves as a metaphor for the overthrow of the native ruling class in south Armagh as a result of the Cromwellian confiscation. Mac Cumhaigh's attitude towards leading members of the catholic laity ranged from extravagant praise of those from whom he received support – such as Arthur O'Neill (‘Tar éis mo shiúil fríd chúigibh Éireann’) of Annaghgad, Co. Armagh, and James Plunkett (‘In Inis Caoin tá an t-óigfhear de fhíor-scoith na Fódhla’) of Iniskeen, Co. Monaghan – to vituperation directed at those who were dismissive of his literary talent, such as the O'Callaghans of Cullaville, Co. Armagh, the owners of a distillery, whom he described as ‘bodaigh na heorna’ (‘the barley churls’) in two songs.
Political and religious themes feature prominently in Mac Cumhaigh's work. Notwithstanding the dispute that attended his marriage, the poet's catholic sympathies are evident from a song (‘A mhic Éamoinn Ruaidh, a shadharclann an tsluaigh’) in praise of Fr John O'Hanlon, who was guardian of the Franciscan house at Armagh from 1748 and subsequently ministered in Creggan parish; and from a work (‘Tá Dealgan ard fán tráth seo coinscleach’) in praise of Fr Dominic Bellew (qv) that was composed on the occasion of his appointment as parish priest of Dundalk in 1772. The song beginning ‘Eadar Foirceal na cléire is Fochairt na nGael’ takes the form of a dialogue between a newly constructed anglican church at Forkhill, Co. Armagh, and a ruined catholic church at Faughart, Co. Louth, in which the former boasts of the power of England while the latter laments the defeats at the Boyne and Aughrim but concludes with a prayer for the success of the Young Pretender, referred to as Rí Séarlas (‘King Charles’). Mac Cumhaigh was also the author of a political aisling (‘Ag cuan Bhinn Éadain ar bhruach na hÉireann’) – a literary genre that was common in Munster but rare in Ulster – which imagined the restoration of O'Neill power in the Fews. Two romantic aislingí, ‘Is tuirseach buartha chuaigh mo shuan aréir damh’ and ‘Ag úr-chill an Chreagáin is é chodail mé aréir faoi bhrón’, are more typical of northern compositions and the latter deservedly occupies an enduring place in the repertoire of traditional Ulster song.
Mac Cumhaigh had no children. He was living with his wife at Tullyard, near Crossmaglen, Co. Armagh, when he died on 5 January 1773 and was buried in Creggan churchyard – the setting for his most popular song. Local traditions differ in detail but agree that his death at a young age was the result of a heavy bout of drinking.