Hi Debra
Thank you for posting your information. It can be helpful to include information concerning which sources you may have already used so others may further your search. I would recommend that you now research what Roman Catholic records exist for Castleisland In Co. Kerry. Viewing the baptismal records may lead to further information e.g place of origin for parents in Cork. Finding an exact place of origin is essential for furthering your research on your Shea family in Cork.
http://www.irishtimes.com/ancestor/browse/
Search the above website under Roman Catholic Parish Maps- Co Kerry- Castleisland.
Alternatively, Emigration records are your best option...Generally more information was given at the port of arrival rather than the port of departure. If you knew which city they arrived at (e.g. Liverpool, New York, etc.), this could be a good place to find more information. -And perhaps even find out an exact place of origin.
Ellis Island: http://www.ellisisland.org/search/passSearch.asp
Castlegarden: http://www.castlegarden.org/
US National Archives/Immigration info: http://www.archives.gov/research/immigration/
Here are some other websites that may be of help to you:
http://www.genealogylinks.net/uk/ireland/kerry/index.html
http://www.genealogylinks.net/uk/ireland/cork/index.html
http://www.nationalarchives.ie/genealogy1/genealogy-records/introduction/
http://www.nli.ie/en/family-history-introduction.aspx
http://ifhf.rootsireland.ie/?gclid=CKLT_Pa4wrUCFYUf4Qod4EoAGg
Debra i hope that this information is helpful. Do not hesitate to contact us again.
Kind regards,
Genealogy Support