McGovern

I am trying to research my great great grandfather.  The only information I have about him is his name was Edward McGovern and that he was born in Ireland, I believe in Cavan County.  He came to the United States sometime prior to marrying my great great grandmother, Jane Kyle, in 1856.  That is about the only information I have regarding him.  I am coming to Ireland in September for a vacation and would love to be able to do some additional research will there.  Any help would be appreciated.