Looking for any information about McGinnis and Fahey

Hi, My ggg-grandfather was Daniel McGinnis.  I believe he left in 1828 but am not sure.  I have found his gravestone which shows he was born in 1808 and that he was from Clontuskert Parish.  My maiden name is Fahey.  All I know is that it's Irish.  I have no idea which part it originates from or anything.  I know my ggg-grandfather Patrick Fay came to I believe Baltimore, Maryland, USA.  I can't find information here.  He may have been a stow-a-way.  All of the older people (who have long since passed on) would say is there was a famine, we're here now, don't worry about where you came from!  I want to know where my roots are!  Any information or ideas where or how to go about looking would be very appreciated!  Thank you in advance, Brenda