My gg-gf Lawrence Carroll (b. 1832 Ire., d. 1910 Brooklyn, NY) was from Cork (according to family stories). He arrived in NYC in 1851 and lived in Wisconsin (according to census/death cert. info)for about 5 years, before settling in Brooklyn, NY with his wife Catherine Cavanagh and 8 children, Ellen, Jane, Mary, Catherine, John, Francis, Margaret, and Anne. I don't know if his father, John Carroll, and mother Mary Reilly, ever lived in USA.
But, I suspect, based on my research, that my gg-gf left behind some family members (siblings? parents?)in WI when he moved to NYC because: 1) according to US Census records, there were a lot of Carroll's in WI in mid-1800's, and 2) I was able to find info only on *direct* ancestors in NYC area (of course, this could be simply because 2nd, 3rd, and more distant cousins are more difficult to find).