In the 1870s John Adamson of England and Robert Adamson of Mount Plunkett are recorded as owning 534 acres and 450 acres respectively in county Roscommon. They may be connected to Adamsons living in county Westmeath in the 19th century.
Contemporary printed sources
- PARLIAMENTARY PAPERS. ''Return of owners of land of one acre and upwards, in the several counties .... in Ireland''. HC 1876, LXXX: 314
- HUSSEY DE BURGH, U. H. ''The Landowners of Ireland. An alphabetical list of the owners of estates of 500 acres or £500 valuation and upwards in Ireland''. Dublin: Hodges, Foster and Figgis, 1878. [available online at www.askaboutireland.ie] : 3