There are Roman Catholic church records for the diocese of Ogulla (Elphin). These date from 1865 for baptismal records and 1864 for marriage records. These are too late in date for you. 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
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, and perhaps even find out an exact place of origin, such as a townland.
You could also try checking the land records called the Tithe Applotment Books (1823-38) or the later Griffith's Valuation (1848-64). Griffith's is freely available here: www.askaboutireland.com or here: www.failteromhat.com Failte Romhat has lots of other useful links you could try looking at.
There are other documents called the Reproductive Loan Fund records. These date from 1838-48 and covers the parish of Ogulla. There are more than 9,000 names in total on this document. This is at the National Archives in the UK http://www.nationalarchives.gov.uk/ with ref. no. T 91.
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)