The Irish immigrant from Moneygall was Falmouth Kearney.
http://blogs.reuters.com/talesfromthetrail/2012/03/20/no-doubts-as-to-obamas-irish-ancestry-now/
Highlighted: This boat manifest shows Falmouth Kearney, who arrived in the U.S. aged 19 to flee the 1850 potato famine in Ireland with his brother-in-law and wife, after travelling from Liverpool, in England, to New York