Finding my roots in Galway, Lackagh, Gardenham

~~I’m Charlie Campbell trying to trace my family roots back to Ireland.  I’m a novice to genealogy.
My Grandfather on my mother’s side was Walter Joyce. His birth date was 21 Aug 1878 according to Ireland Birth and Baptism 1620-1881
I also know from his US Marriage Record from 1907 that he was from Galway, Ireland.  He was very specific in fact to list his place of birth as Gardenham, Ireland.  He must have been very proud of this fact.   He also listed his parents and my great grandparents as James Joyce and Helen Kilgarriff. 
The 1901 Irish census seems to confirm that both James Joyce ( approx. Birth year 1838/39 ) and Ellen Kilgarriff Joyce ( approx.. 1841/42) were living in Gardenham, Lackagh in 1901.
Walter Joyce does not appear on that 1901 census.  I believe, he had immigrated to the US and arrived in ELLIS ISLAND in 1899 on the Campania.
I can see traces of Kilgarriffs and Joyces in the earlier 1800’s in records from Ireland, Galway, Lackagh, Gardenham.  It appears that a Thomas Joyce may have been a land owner in Gardenham.  And there are also references to an earlier Walter Joyce of Merview or Mervue buying land in Lackagh, Gardenham.
My Grand Parents James Joyce and Ellen Kilgarriff appear from Irish records to have had the following children, Margaret 10 May, 1867, Peirce 27 July 1869, William 19 Dec 1871, Martin 8 Nov 1873, Winifred 13 july 1876, James 17 Oct 1880.  In addition it appears they were christened in 325 Turloughmore, Gal, Ire. I believe they may have had more children including Delia Joyce born (approx. 1881/82 as she appears on the 1901 census.
I’m hoping that someone in the Lackagh Parish has some knowledge to link my grandparents James Joyce and Ellen Joyce Kilgariff to earlier ancestors in that area.  
Also I’d love to know if there is any information on their other children I listed.   If any remained in that area and if I might have cousins still in the Lackagh Parish. I believe there are some references to a Peirce Joyce in the early 1900’s.
Third, I’m curious abort my grandfather’s sister Delia Joyce 1881/82.  I know she also immigrated to the US but I can’t seem to find her trail.
History of that area would also be an interest to me.
Thanks for any help!.. The Walter Joyce trail is my clearest at this point.  All my ancestors are Irish but the trail to the Campbell’s is not very clear as they can during the famine in 1850 ish.  I have no trail on Quinn, Melia or Cahill or Inge who all are part of my ancestory.