A: In most cases, Irish surnames are relatively common. You need to determine a specific place of origin in Ireland from United States records before you go searching in Irish records—unless you have a really uncommon surname that comes from only one or two counties in Ireland.

Naturalization papers can be a good source for this information, depending on the time period and locality. Remember, you will want to look at both the Declaration of Intention and the Petition for Naturalization. These two documents were usually filed years apart and could be filed in different courts. They may contain significantly different information.

Records generated when the immigrant ancestor died also are good possibilities for naming a place of origin in Ireland: death certificates, cemetery registers, tombstones, church burial records, obituaries, funeral home records, funeral cards. It is also helpful to know the immigrants' parents' names, especially the mother's maiden name. You can find a detailed discussion of immigrant research in our new book, A Genealogist's Guide to Discovering Your Irish Ancestors by Dwight A. Radford and Kyle J. Betit (Betterway Books,).

Also, you should be tracing not only your grandfather but all other relatives who came over from Ireland to see if records of any of them tell at least the county they came from in Ireland. This includes siblings or other relatives who settled in other countries abroad.