Thanks for the information.
Unfortunately, the family came to the United States before the Ellis Island Project.
It appears that they came about 1864 which was when the specific search subject was eight years old.(b. Apr. 1856, per 1900 Fed. census)I haven't figured out yet when they came to California.
Do you know how to access Griffith's Land Valuation of 1855?
Fortunately, they were still in Ireland for the 1855 Griffith's Land valuation.