Those attempting to track down their Irish ancestors' port of entry shouldn't forget about New Brunswick, which lies closer to Ireland than Boston or New York. Irish Famine Migration to New Brunswick from the Provincial Archives has 23,318 records of Irish arrivals between 1845 and 1852. If your ancestors emigrated at an earlier date, check Port Returns [including Passenger Lists], 1816-1838: 10,412 indexed records of arrivals with digitized images of the passenger manifests.

Take a look at: http://archives.gnb.ca/APPS/PrivRecs/IrishFamine/?L=EN