Blacker, William (1776–1850), land agent and agricultural writer, was born in 1776, probably in Co. Down, the third of four sons of St John Blacker, a clergyman who was then curate at Kilbroney, and his wife Grace, daughter of Maxwell Close of Elm Park, Co. Armagh. He became land agent to Lord O'Neill in County Antrim and by 1815 was agent to the earl of Gosford (qv) at Markethill, Co. Armagh, at the unusually high salary of £1,000 p.a. He also became agent to Lord Bangor (Co. Down), his cousin Col. Maxwell Close (Drumbanagher, Co. Armagh) and the governors of the Dungannon Royal School (Co. Tyrone). On the Gosford and Close estates he introduced a new system of management which encouraged the growing of green crops (especially clover, tares and rape) and feeding them to cattle in stalls; he introduced expert bailiffs to carry out educative and supervisory work among tenants. By 1836 he had procured in Scotland some 60 such ‘agriculturalists’ for employment in different parts of Ireland. Blacker's writings on agriculture included Prize essay addressed to the agricultural committee of the Royal Dublin Society on the management of landed property in Ireland (1834); An essay on the improvement to be made in the cultivation of small farms by the introduction of green crops and housefeeding the stock thereon (1834; 5th ed., 1837; revd ed., 1845); The claims of the landed interests to legislative protection (1836); Review of Charles Shaw Lefevre, Esq.'s letter . . . [on] the present state of agriculture (1837); An essay on the best mode of improving the condition of the labouring classes of Ireland (London, 1846).
Blacker was a witness before the Devon commission (1844) and the house of lords colonisation committee (1847). Originally an opponent of the consolidation of holdings, by the time of the Famine he had become inevitably pessimistic about the prospects of small farmers. A gold medallist of the RDS, he was elected MRIA (9 May 1842). He has been described as ‘one of the foremost and most enlightened Irish land agents of the century’ (Thompson). His letter-books are in the Gosford papers in PRONI, D 1606. Blacker died without issue on 20 October 1850 at his home at Armagh. His brothers all had prominent careers: Samuel (1771–1849), a clergyman, inherited Elm Park from their mother; Maxwell (1773–1843), a barrister, became a queen's counsel and chairman of the Kilmainham sessions; Valentine (1778–1823) and St John (1786–1842) both rose to be colonels in the Madras army, the former being also surveyor-general of India, the latter envoy to Persia. William Blacker the land agent is not to be confused with Col. William Blacker (qv) (1777–1855) the prominent Orangeman and a writer of verse; they shared a common ancestor (great-grandfather and great-great-grandfather respectively) in William Blacker (d. 1732) who fought for William III (qv) at the Boyne and married three times.