Could you please post your message on the Killala parish page here: http://www.irelandxo.com/group/killala-mayo
There are Roman Catholic church records available for the diocese of KIlmoremoy (Killala). These date from 1823 for baptismal, marriage and burial records. You can find these at the National Library of Ireland, Pos. 4231, or the Church of Latter Day Saints, 1279205; 1279205, 3. If you have any difficulty, you could try writing to the parish priest for more assistance.
Civil registration records are available from the General Register Office (GRO). These start from 1864 however. You can access the website here: http://www.groireland.ie/research.htm
There are Roman Catholic church records available for the diocese of Killala. These date from 1852 for baptismal records and from 1873 for marriage records.. You can find these at the National Library of Ireland, Pos. 4231, or the Church of Latter Day Saints, 1279204.
Have you tried checking the Ellis Island records (www.ellisisland.org) or the Castle Garden records (www.castlegarden.org)? Generally, more information was given at the port of arrival rather than the port of departure. If you knew which city they arrived at, this could be a good place to find more information.
You could also try checking the land records called the Tithe Applotment Books (1823-38). Microfilm copies of the books for all of Ireland are available at the National Archives of Ireland (NAI) http://www.nationalarchives.ie/genealogy1/genealogy-records/tithe-applotment-books-and-the-primary-griffith-valuation/ or the Church of Latter Day Saints (LDS).
The Tithe Applotment List will be useful to you, or at least interesting for you. These lists constitute the only nationwide survey for the period, and are valuable because the heaviest burden of the tithes to the Established Church, the Church of Ireland, fell on the poorest, for whom few other records survive. The information in the Tithes is quite basic, typically consisting of townland name, landholder's name, area of land and tithes payable. Many Books also record the landlord's name and an assessment of the economic productivity of the land. the tax payable was based on the average price of wheat and oats over the seven years up to 1823, and was levied at a different rate depending on the quality of land. For Parishes where the registers do not begin until after 1850, this information can be useful, as they are often the only surviving early records. They can provide valuable circumstantial evidence, especially where a holding passed from father to son in the period between the Tithe survey and Griffith's Valuation.
There are a few other documents you could try:
1842 Freeholders list. National Archives of Ireland (NAI), OP/1842/71.
1845 Defendants at Mayo Summer Assizes (Notebook of Justice Jackson). NAI M.55249.
1850 Voters' lists. South Mayo Family History Research Journal, 1996, 27-41.
There's a book by Brian Smith called 'Tracing your Mayo Ancestors' (1997).
There is also some estate records for the Kilmoremoy area. The landlord The Earl of Arran: National Library of Ireland Ms. 14087; leases on the Mayo estate, 1720-1869, mentioning lives of the leases. NLI Ms. 14086; valuation survey of the Mayo estates, 1850- 52. All tenants. Covers townlands in parishes including Kilmoremoy.
Please make sure you link anyone else in your family who is interested in their Irish heritage to our site - and indeed anyone else you know of Irish heritage.
Genealogist (Ireland XO)