My interest in the Croak line is because of a marriage between Mary Dunphy and Jeffery Croak. Mary being a sister to my gg grandmother Margaret Dunphy who married Patrick Breen. Mary Croak is mentioned in her nephew Michael Breen's obituary. This Breen family is buried in the Old Croak Settlement cemetery in Magnolia twp, Rock, WI. It has been passed down and in one of the Breen child's obituary that they first went to Janesville around 1850. I have not found them in Janeville, but by 1860 they were found in Sauk. There are quite a few Croak, Dunphy and a few Breen families found in the 1824 tithe for Parish Ballingarry, Tipperary. Just did a quick check and note a few Farrell's also.
http://www.rootsweb.com/~irltip2/tab3_1.htm Do you know where in Tipperary your Croak family is from?
Sue