Many people in this area (Upstate New York) have Irish ancestry. Family Sherlock even has a little, but never thought much of it except on St. Patrick's Day. It turns out she was very close to her ancestor's hometown in 1989 but did not know it! The following is a good example of a research report you could hire Family Sherlock to write for you.
Although most of my heritage is German, with a little British and Sicilian, there is some Irish blood in my veins. My great-grandma (who I remember calling Big Grandma) Ida Glossner's mother was Margaret (Margret) McCarthey Goodman, and she was born in Ireland1 in August, 18652.
Family lore told us two things- she immigrated to the US on the "Bremen" from Cork to Baltimore, and she was a cousin of the boxer, John L. Sullivan. I was not able to find immigration records as many from Ireland to Baltimore were lost. Cork was a main port for Ireland, and it did not necessarily mean that the McCarthey's lived there. The information about the ship they sailed on was passed on to me by my paternal grandmother, Ida's daughter-in-law. I was not successful searching for Margaret's birth records in Cork, as there were many McCartheys, but then I changed my tactic.
John L. Sullivan's father was Michael Sullivan of Abbeydorney, County Kerry3. When I search in Kerry for Margaret McCarthey, with a mother named Sullivan, I found her birth record from Sneem, County Kerry. Her parents were Charles McCarthey and Mary Sullivan, and her birth date was August 19, 1865.4
I was able to confirm this is my great-great-grandmother because I also found her death certificate which gave her parents' names as Charles Mccarthy and Margaret Sullivan and her birth date as August 18, 18655. I was originally confused by this because she died in Illinois, but one of her children lived there. Otherwise the matches are very close.
Areas of further research are to trace the McCarthey and Sullivan lines back further, and to make a more definitive connection between Mary Sullivan and John L. Sullivan. Also, further documentation into Margaret's relocation from Rochester to Chicago should be researched.
1"New York, County Marriages, 1908-1935," index and images, FamilySearch (https://familysearch.org/pal:/MM9.1.1/XVGG-MHV : accessed 17 Mar 2013), August C. Glossner and Ida M. Goodman, 1910.
2"United States Census, 1900," index and images, FamilySearch (https://familysearch.org/pal:/MM9.1.1/MSJH-JZN : accessed 17 Mar 2013), Margret Goodman in entry for Frank Goodman, 1900.
3 http://en.wikipedia.org/wiki/John_L_Sullivan#cite_note-1, accessed 3/17/2013.
4"Ireland, Births and Baptisms, 1620-1881," index, FamilySearch (https://familysearch.org/pal:/MM9.1.1/F557-4ZQ : accessed 17 Mar 2013), Margret Mc Carthy, 19 Aug 1865.
5"Illinois, Deaths and Stillbirths, 1916-1947," index, FamilySearch (https://familysearch.org/pal:/MM9.1.1/N3HZ-GXZ : accessed 17 Mar 2013), Margaret Goodman, 25 Feb 1941.