Must be many variant spelling of another surname, the Oxford Names Companion inseveral editions but in the 2001 gives no entry but several variants under McKay, eg McGhie etc
There are no McCaa's in the registry for Belfast Clifton St cemetery
In the new
www.familysearch com pilot project for BMDs etc for Ireland just one
Name: John McCaa
Registration district: Newtownards
Record type: MARRIAGES
Registration date - quarter and year: 1849
Film number: 101242
Volume: 9
Page: 16
Digital GS number: 4195888
Image number: 00420
Collection: Ireland, Civil Registration Indexes 1845-1958
on
www.nifhs.org/ there are 4 entries which boil down to 2 at Garvaghy via
www.angelfire.com/falcon/bannvalley/ Garvaghy and 2 at
www.billmacafee.com/1740returns/1740religiousreturnsnames.htm at
At PRONI’s new eCatalogue there are 3 entries unchecked if relevant
At the freeholders database at
www.proni.gov.uk/Result 1 McCaa John Carnlough D/1364/L/1
Result 2 McCaa Michael Ballywilliam D/654/A3/1B
Result 3 McCaa Samuel Ballywilliam D/654/A3/1B
Result 4 McCaa Hugh Carrickmannon
nil at the Ulster Covenant database at PRONI
nil at the Wills database at PRONI
Over in England etc from
www.freebmd.org.ukabout 10 McCaa Births are recorded from 1899 onwards
about 7 McCaa Marriages are recorded from 1846 onwards
about 7 McCaa Deaths are recorded from 1846 onwards
One of the variant spellings used is McCahey, but my ulster ear thinks its much more like McKay, but best to me is McGhie or McKie, all of which are getting close to Mackie depending how you say it. I dont think its McKee.
Scotlandspeople.gov.uk seems a good starting point as advocated by TheWhuttle,
have you exhausted St Annes Cathedral records?
Good luck, Jim