Otho Oscar Baker was born on 3 June 1880 in Gonzales County, Texas, to farmer James Alexander "Jim" Baker and his wife Laura Lee Squires. He married Della Pearl McGlaun, 15 March 1905, at the Methodist Church in Guffey, Texas. They had two children, Beatrice Pearl "Bea" and James Herman Baker. Their son died, an infant. Otho and Della were divorced; Otho lived in San Antonio, Texas, then later with a niece in Baytown, Texas. He died, 29 December 1956, aged 76, in Baytown, and was buried near three of his siblings at Earthman Resthaven Cemetery in Houston, Texas.