Per his Washington State Certificate of Death, he was the son of Henry Barnum born New York and Miss Richardson. In the Adams County News, Wednesday, May 11, 1904, George H. Barnum is listed as the Administrator in a Notice To Creditors To File Claims against the Estate of Darwin L. Barnum, deceased. The parents of his brother, Darwin L. Barnum were listed as William Barnum and Sophrona Richardson Barnum.
On November 26, 1878 as George H. Barnum, he married Elizabeth R. Urquhart at Emmet, Iowa. They were the parents of three children including Ida E. Barnum born about 1864 in Indiana and Jessie M. Barnum Miller born 1877 in Iowa. Per The Spokane Review dated Saturday, September 23, 1893, Elizabeth R. Barnum sued George H. Barnum for a divorce on the ground of desertion. The complaint stated they were married on April 12, 1860 at La Porte, Indiana and separated in April 1891. The divorce was granted on September 25, 1893.