The Public Record Office Northern Ireland (PRONI) has published online all the Valuation Revision Books (VAL/12/B) in its holding for the period 1864 to 1933: http://applications.proni.gov.uk/dcal_proni_val12b/. These are invaluable sources of information for the names of people occupying or leasing property in the area of Markethill and District. The Valuation Revision Book database is searchable by townland and parish. For the purposes of land valuation, only landowners and/or lessor names were recorded.
The above image is a page on Acton townland in Ballymore parish from PRONI's Valuation Revision Books, PRONI Reference: VAL/12/B/15/23A (1865 - 1879).
This page is from PRONI VAL/12/B/10/34A (1866 to 1882) for the townland of Bryandrumin Mullaghbrack parish. The map references are to Ordnance Survey map 17 (also consultable in PRONI). For example, map reference 4a on the Ordnance Survey 17 map is to land leased by James Gray from the Earl of Gosford. The land is described as containing a house, flax mill, offices[or farm buildings] and land. Sometimes a name is stroked through to indicate a lessor has moved away oris deceased and the name of the subsequent lessor has been entered above.