John Brennan : Short Biography

I really know little about my Brennan family from Tralee, County Kerry. My GGF was Patrick Brennan and came to the America via Canada in 1851. He was 16 years old at the time. His father was John Brennan and mother was Julia Sullivan. Patrick was born 17 March 1835. He had half brothers Louis, Francis, and John all of whom came to America but I have no information as to when.. Unfortunately that exhausts my information on the Brennans in Tralee.