William was married twice. His first wife is unknown, but his three known children by her were 1)James BLAIR b. 12 Jan 1813 in Greene co PA, d. 17 Jun 1889, Jo Daviess co IL m. Catherine MARSH, b. 10 Feb 1817, OH, d. 12 Nov 1879, Jo Daviess co IL, m. in Stephenson co IL on 24 Jul 1837; 2) William BLAIR, Jr. b. 12 Aug 1817, Greene co PA, d. 17 Jun 1854, Wards Grove, Jo Daviess, IL m. date unknown, bef 1 Jun 1840, Ann Sophia GIBSON, b. 25 Mar 1819, PA, d. 23 Dec 1852, Wards Grove, Jo Daviess, IL and 3) Deborah BLAIR b. a/1818, Greene co PA, d. Oct 1854, Wards Grove, Jo Daviess, IL, m. abt 1838 David ERLEWINE/EARLYWINE b. abt 1814 VA (probably Ohio co, now WV) d. 14 Sep 1892, location unknown. Deborah is buried in the Blair Cemetery in Wards Grove, as is her father, William, brother James, and brother William Jr. along with many other family members. I have used all the Jo Daviess co records available on the 'net, plus other 'net sources, plus all the censuses., in my research, so far. This family is believed to be collateral to my husband's direct BLAIR line, which I've been researching for over 40 years. It is believed that William BLAIR, Sr. is the son of James BLAIR, b. 16 Jul 1752, VA, d. 26 Aug 1824, Ohio co VA/WV (left a will) and his unknown first wife. My husband is a descendant of James' 2nd wife, Anna Amelia BRAYFIELD HAGERMAN, whom he married in Hagerstown MD on 5 Apr 1795. I would love to share data with any descendants and also find a present day BLAIR male descenant of William BLAIR, Sr. to participate in the BLAIR DNA project (at no expense to the participant) Thanks for any help with these families and finding present day descendants, male or female. E-mail me or post a response. I also know that William BLAIR, Sr. married for a 2nd time as her 4th husband, to Phoebe G. CRAM on 4 Oct 1860 in Stepehenson co IL. Phoebe was the dau of Nathan CRAM and Rachel DUTTON. William and Phoebe had no children, but there were intermarriages among their descendants.