I am not related! If you get started researching, you'll thoroughly enjoy the experience! View online death certificate of your great grandfather: H. O. Barclay (11 Sep 1880 - 2 May 1952) at http://pilot.familysearch.org/recordsearch/start.html#start
Then view "Stone/Lambert Family Tree" owned by ChristinaStone88 at http://trees.ancestry.com/tree/12304026/person/-274850500
Digest that then view 1900 census of Hood County, TX-Precinct 1-District91-Image 26. Note your great grandfather had a twin brother, James. He also had younger twin siblings, Earl and Ethel. Any twins in your family? Anyway, the parents were Thomas Humphrey Barclay and Serena Elizabeth McCommas who wed 15 Oct 1874 per pedigree submitted by Robert S. Shields of Seattle, WA. That's viewable at familysearch.org. Lots people have saved records on Thomas H. Barclay. You probably have lots of info on Hollis O.? Guess what? Doesn't seem to be a lot of interest in Hollis O.'s twin? Let's fix that? Hallis(sp) O. Barclay registered for WWI Draft in Somervell County with a birthdate of 11 Sep 1880. Wife Clarence was next-of-kin. James Barclay registered for the draft in Hardeman County with same birthdate. Wife Rosa Lee was next-of-kin. James B. Barclay and Rosa Lee Cross married about 1903 per 1910 Hardeman-Damsite-District 132-Image 1. Search for Jim Barclay. In 1920 Hardeman-Precinct 4-District 125-Image 13, the surname was corrupted to Blarclay. In 1930 Hardeman-Precinct 4-District 11-Image 1, search for Jim B. Barclay. James B. Barclay (11 Sep 1880 - 8 Jan 1956) and wife Rosa Lee Barclay (19 Oct 1884 - 29 Jan 1956) have online death certificates. James' son Earl wed Jewell Dee Boswell and begat Harold J. Barclay. Harold wed Rosita (Rose) Mae Licostie and there are three births on the database. Son Harold Earl Barclay has a birth record listed, also. Straight to the point! Search birth index for surname Barclay in Potter County. They are descended from James B. Barclay.