Hi Angela,
I'm a DUNCAN whose ancestors are from Northern Ireland (have not found a connection to the Drumnakilly ones). In my hunt, I have been building a database of many DUNCAN families in Northern Ireland.
As you now know, the DUNCAN's of Drumnakilly go by the surname of DUNCAN and DONAGHY.
I wondered why that would be and Googled the Irish pronunciation of DUNCAN / DONNCHADH.
https://forvo.com/word/donnchadh/This link has the Scottish Gaelic pronunciation, and if you scroll down there is the Irish pronunciation which does sound something like "DONAGHY". So, I think this explains the surname discrepancy. / This was a mind opening revelation to me!
PRONI.gov.uk (image scans) Public Record Office of Northern Ireland
VALUATION REVISION BOOKS.
Townland of Drumnakilly, Tyrone, you can follow the years to see the transfer of occupiers of Number 20. - There are no DUNCANs in the Occupiers listings.
Starts in 1860 with an ANDREW DONAGHY crossed out, "Dec'd" [deceased] then added is HENRY DONAGHY.
1871 HENRY DONAGHY is crossed out then added is JAMES DONAGHY.
1908 JAMES DONAGHY is crossed out and added is WM DONAGHY.
1912 the occupier is WM. JAS. DONAGHY.
WILLIAM JAMES DUNCAN is listed on the 1911 Census of Drumnakilly. So, together with the Tenement Occupier listings and the Census, we definitely know DONAGHY is DUNCAN.
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There are 2 JAMES DUNCANs who married HAMILTON women.
JAMES DUNCAN (son of HENRY) & MARGARET HAMILTON lived and died in Drumnakilly.
JAMES DUNCAN (son of OWEN) & MARY JANE HAMILTON.
JAMES lived in Drumnakilly at the time of his marriage. I am still researching this couple.
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Stepping back to HENRY DUNCAN. I believe I have found 3 children for him.
1. JAMES DUNCAN (MARGARET HAMILTON)
2. MARGARET JANE DUNCAN & (WILLIAM REDMOND)
WILLIAM is listed as deceased on the 1864 birth of their son JOHN HENRY REDMOND.
I don't know what happened to MARGARET & her son.
3. ANNABELLE / ANNA BELLA DUNCAN & (SAMUEL McCAUSLAND)
FamilySearch.org (text index transcript with image scans)
Massachusetts, Index to Boston Passenger Lists
[typed card, front & back]
IMMIGRATION
Event Place: Boston, Suffolk, Massachusetts, United States
Front of Card: SAMUEL McCAUSLAND/ Age: 26 (1846)
Port: Boston
Arrived Date: Mar. 4, 1872
Ship: S.S. “Siberia”
Occupation: Labr.
Birth Place: Ireland
Last Residence: England*
[* "England" this is incorrect. They did not live in England. The ship originated in Liverpool, England then picked up passengers in Ireland.]
Destination State of which to become inhabitant: - - - (blank)
Back of Card: [at very top of card in dark shadow]
Mrs. ANNABELLA McCAUSLAND 26
JAMES 2, MARGT JANE 1
NOTE: There is also another immigration document scan of the full passenger list.
I haven't gotten to type out that one yet.
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DerryDuncan
My DUNCAN's came from the Londonderry/Donegal, Ireland area... to Quebec, Canada, then to Massachusetts, USA.