Career
A native of Ireland, Smith was in his late twenties when he arrived in South Carolina in the months immediately following the end of the Revolutionary War. In 1804 he was elected as a Republican to the Ninth Congress for the term lasting from (March 4, 1805 – March 3, 1807). O'Brien Smith was in his mid-fifties when he died in South Carolina, nearly three decades after arriving in the United States.
There is no known historical record indicating the date and place of his birth, although the year is generally estimated to be 1756 and the country of birth is presumed to be Ireland. He was interred in the burial ground of the colonial Chapel of Ease of St. Bartholomew's Parish, Colleton County, near Jacksonboro.