Until Daniel O'Connell managed to get the law changed (and instituted non-sectarian cemeteries), Catholics and Dissenters (ie any Christian not from the Church of England) could not be buried in Protestant (CofE) churchyards, and were not allowed to have their own cemeteries.
Here's the Dictionary of Irish Biography piece on Roddy McCorley. Surprisingly, there's no piece in ainm.ie - well, I suppose they're more interested in people with an involvement with the language - but it's a pity because they're terribly meticulous.
Northern Ireland is odd, but certainly in the Republic of Ireland nobody gives a fiddlers fuck about Protestant and Catholic any more. Except for a tiny teeny teenshy percentage of sectarian lunatics, regarded with impatient amusement by the sane.