George Mason married Jane Copeland on 29 Jan 1833 in the Roman Catholic parish of Aglish. (So you may also want to join the IrelandXO Aglish community as well). Their witnesses were M. Semple & Mary Tresham.
His occupation was recorded as "SOLDIER 27TH REGT". – the 27th (Inniskilling) Regiment of Foot.
So if you add him to our Ancestors Roll-Call for Castlebar, Aglish and Longford (see below) be sure to tick the Special Group Military Ancestors box. Also, link him to the Castlebar Military Barracks building to discover more.
As for children, the only record showing up (in Ireland) places them in Longford in 1850:
George Mason Jr baptised 08-May-1850.
Parents George Mason & Joanna Copeland.
Godparents: Thomas O'Neil & Esther Bellews
One of the reasons no other children turn up on record here could be that between 1837 and 1847 the 27th Regiment was engaged in several of the Xhosa Wars in South Africa.
Jane and George do not turn up on any records in Co. Mayo or Longford as parents, godparents or witnesses.
Hope this helps!
On an aside, the only Copeland on record in Co. Mayo turns up once (in the RC Parish of Aglish)...
Samuel Copeland & Julia Williams (m. 1845 in Clones, Co. Monaghan) were residing at Mount Gordon Castlebar when they baptised Mary Copeland on 14-Dec-1857.Godparents: Michael & Mary Gallagher. Copeland was a soldier in the 47th regiment.