A Leinster family who held a small estate in county Roscommon. Their residence in the 19th century was Abbeville, Malahide, which was the home of Charles J. Haughey in more recent times.
- By the early 19th century this family was living at Abbeville, Malahide, county Dublin. In the late 20th century Abbeville was the home of Charles J. Haughey, see Mary Rose Doorly ''Abbeville'', published by Townhouse (1996). At the time of Griffith's Valuation William Cusack held the townland of Ballymurray, parish of Elphin, barony and county of Roscommon. In the 1870s his wife Mrs Sophia Cusack of Abbeville House is recorded as owning 291 acres in county Roscommon and 423 acres in county Dublin.