genealogy of john leary (o'leary)

This is the information I have about John Leary (O'Leary) and wife Joanna Sulllivan. John Leary was born May 16, 1820 and baptized on June 26, 1820 in the parish of Desertserges in County Cork.  John married Joanna Sullivan on March 2, 1851 in the Parish of Innishannon.  John Leary had two children John Jr baptized July 2, 1852 in Clontead and Mary baptized May 2, 1854 in Ballinhassig in County Cork.  John Leary came to America around 1856.  I need to know what town he lived in and the parents of both John Leary and Joanna Sullivan.  Please help.  This is my last hope of finding information on John Leary and Joanna Sullivan.  Any help will be greatly appreciated.  Thank you.

Pat Rogers.