First found in Connacht, where they were seated from ancient times.

To escape the religious and political discrimination they experienced primarily at the hands of the English, thousands of Irish left their homeland in the 19th century. These migrants typically settled in communities throughout the East Coast of North America, but also joined the wagon trains moving out to the Midwest. Ironically, when the American War of Independence began, many Irish settlers took the side of England, and at the war's conclusion moved north to Canada. These United Empire Loyalists, were granted land along the St. Lawrence River and the Niagara Peninsula. Other Irish immigrants settled in Newfoundland, the Ottawa Valley, New Brunswick and Nova Scotia. The greatest influx of Irish immigrants, however, came to North America during the Great Potato Famine of the late 1840s. Thousands left Ireland at this time for North America and Australia. Many of those numbers, however, did not live through the long sea passage. These Irish settlers to North America were immediately put to work building railroads, coal mines, bridges, and canals. Irish settlers made an inestimable contribution to the building of the New World. Early North American immigration records have revealed a number of people bearing the Irish name O'Bierne or a variant listed above, including: Bridget Birne, who sailed to Quebec in 1849; Michael Beirne to Philadelphia in 1867; Patrick Beirne to Philadelphia in 1869; Martin Beirn to Philadelphia in 1872.

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