A Bernard McDermott, not married in 1847, changed his surname to Mack and moved to upper state NY by 1850. The man was from Ireland and I have information on the 'root' family. If you have a Bernard Mack born 1820 with a hint of Irish, I may have your tree. His parents were Hugh and Eliza McDermott, brothers: Hugh,James,John, and Will. Sisters: Anne,Bessy,Ellen,Rosanna, and Susan.
The family unit came to US from Kilglass parish, Co. Roscommon, Ireland in 1847 on the 'Roscius'. Bernard has a wonderful history as a young man in Ballykilcline, Ireland leading a rent strike. Please contact direct.