The earliest known O Beirne immigrant, Abbé Bierne, in 1733, was not a voluntary emigrant from Ireland but was sent by his Church from France to Canada. The earliest assumed to be direct from Ireland was Nathaniel Beirn who was listed in the colonial census of 1781 as a resident of Middletown Township, Monmouth County, New Jersey. The next known, and the first to be well documented, was Andrew Beirne who emigrated (as O'Beirne) from Dangan in 1793 to Philadelphia and on to Virginia. O Beirne immigration seems to have been only intermittent before the Irish Famine of the 1840s after which it became virtually a tradition.
        The usual stimulus to emigrate was to get away from bad living or political conditions in rural Ireland in the hope of finding work and relative freedom in urban America. Later in the 1900s it became increasingly by the trained and the educated in the expectation of finding better opportunities for employment and advancement than in Ireland. As compared with emigrants from Continental Europe, Irish emigrants returned relatively rarely to live permanently in their homeland. O Beirnes were no exception.
        In the United States the O Beirnes were and are concentrated in the northeast: judged from listings in telephone directories about 37 per cent live in New York or New Jersey and 80 per cent east of the Mississippi. States outside the northeast with significant numbers are Florida (which gets retirees from the northeast), California, and Texas.
        That concentration is from a combination of historical reasons: the great majority of the immigrants arrived in New York, earlier in Philadelphia and Boston; new immigrants tended to settle where there were already relatives or friends in Irish communities centered on Catholic churches. There they often had large families, for instance uillean piper Martin P. Beirne claimed that a granduncle in East Orange, New Jersey, had 22 sons; and 1833 immigrant John Ferris Beirnes is primarily why that name (with the terminal s) is the most common version in Canada.
        Those communities were visible targets for the anti-foreign, anti-Irish and anti-Catholic prejudice and discrimination that began seriously in the 1850s and continued into the 1900s. It was in attempts to avoid being recognized as obviously Irish that so many O'Beirne emigrants of those times dropped the O' in the Atlantic. The name Beirne outnumbers O'Beirne by about three to one in the United States as a whole. However O'Beirne predominates in Massachusetts and Wisconsin and the two names are about equal in Michigan and Virginia. That O Beirnes in Irish and Catholic communities could have been repressed in the past by discrimination is implied by the relatively high proportion of the more notable achievers that were of different religions or locations or both.
        By the later 1900s the Irish, including the O Beirnes, had become fully accepted as Americans and Canadians, though immigration had become restricted.