James H. Irwin, b. 25 Mar 1820 in Oswego, Oswego County, New York, d. 13 Feb 1909 in Sterling Center, Cayuga County, New York, son of James G. Irwin & Mary White. He married Mary Ann Armstrong in 1845 in Oswego County, New York.
James Harvey Irwin, b. 16 Sept. 1825 in Mifflin, Juniata County, Pennsylvania, d. 9 Feb 1901 in Pittsburgh, Allegheny County, Pennsylvania, son of James Irwin & Margaret Whittaker. He married Eliza West on June 10, 1860 in Pennsylvania.
James Kennedy Irwin, b. 18 Sept. 1862 in Washington County, Pennsylvania, d. 1927 in Pittsburgh, Allegheny County, Pennsylvania, son of James Harvey Irwin & Eliza West.
John Arthur Irwin, b. 17 Jun 1853 in Elphin, County Roscommon, Ireland, d. 1 Jun 1912 in Manhattan, New York County, New York, son of John Irwin & Unknown Harkens. (Descendant of Sir William de Irwin, the armour-bearer of King Robert Bruce)
John Robinson Irwin, b. 29 Dec 1853 in Mecklenburg County, North Carolina, d. 28 Jun 1931, bur. 30 Jun 1931 in Charlotte, Mecklenburg County, North Carolina, son of Batte Irwin & Mary Hayes Robinson. He married Margaret Henrietta Henderson on February 19, 1879 in Mecklenburg County, North Carolina.