Timothy Ragan born 1678 Ireland died Anne Arundel County Maryland, USA

I am trying to find out the parents of Timothy Ragan, sometimes spelled O'Riagan, who was born about 1678 probably in Ireland.  He migrated at some point to the Unites States,  Anne Arundel County in the state of Maryland. On Saturday, November 24, 1703 he married Mary Lary (O'Leary) in St. Margaret's Parish in same county and state.  Mary was born about 1686 probably in Ireland. My Great Grandfather told me that three brothers came over to the United States from Ireland.  He said once they arrived in America they had a disagreement and all three went their seperate ways, each one changing the spelling of their surname.  I am just beginning my Irish heritage search so any information would be welcome! My direct email is: tracyliekhus@gmail.com