James S. O'Brien, b. 20 May 1859 in Cold Springs, Jefferson County, Wisconsin, d. 24 Apr 1910 in Milwaukee, Milwaukee County, Wisconsin, son of Patrick O'Brien & Sarah Smith. He married Julia Carroll on May 28, 1895 in Milwaukee, Milwaukee County, Wisconsin.
John Newton O'Brien, b. 15 Sept. 1837 in Chester, Delaware County, Pennsylvania, d. 22 Apr 1900 in Milwaukee, Milwaukee County, Wisconsin. He married Anna Ingraham Smith in Wisconsin.
John O'Brien, b. 1750 in Scarborough, Cumberland County, Maine, d. 8 May 1832 in Brunswick, Cumberland County, Maine, son of Morris O'Brien & Mary Cain.
John O'Brien, b. 6 Jan 1847 in Tralee, County Kerry, Ireland, d. 25 Feb 1907 in Chicago, Cook County, Illinois, son of Patrick O'Brien & Unknown. He married Mary Lane in 1870 in Chicago, Cook County, Illinois.
John O'Brien, Jr., b. 10 Aug 1879 in Chicago, Cook County, Illinois, d. 22 Oct 1916 in Chicago, Cook County, Illinois, son of John O'Brien & Mary Lane. He married Mary McNeill.
John P. O'Brien, President Atlantic Coast Realty Co., Ex-President New York & Staten Island Land Co.
Joseph O'Brien, b. 1834 in New York, d. 18 Mar 1901 in Manhattan, New York County, New York, son of William O'Brien & Eliza West.