I think your Doonan could be a misinterpeted variation of the name Ronan. My GG Grandfather was a Patrick Ronan b. about 1836 in Ireland to Thomas and Elizabeth or Mary Elizabeth Gilhooly. Patrick came to NYC about 1849 and I have an 1850 US Census for him under the spelling Roonan living with the following persons; Patrick Cunningham, Margaret Cunningham,thir son John, another Jon Cunningham, Elizabeth Donnelly, Neal or Michl (Michael) Boyle; there is also a Mary Roonan age 30. This could be Patrick's mother but she would have been very young.
I found a Thomas Gilhooly, piano maker, living at 744 2nd Ave on a Naturalization Index from 1868 in NYC a PJ McCaffrey at 16 E. 58th St., was his Witness. Patrick and his wife Anna McCaffrey Ronan were already living at 221 E. 58th. I am certian these to have a connection to my family in some fashion.
If you see this and think we should compare notes, contact me here at Ancestry or at firstname.lastname@example.org
; indicate Gilhooly.