John C. Douglass was born around 1828 in Ohio. He married Mary Phillips on December 29, 1857, and they had at least three children: Clarence, born around 1859; Minnie, born around 1861; and Jennie, born around 1876. They lived in Cambridge, Ohio, and Douglass worked as an editor.
He received a commission as a 1st lieutenant in the 78th Ohio Infantry on October 22, 1861. The regiment took part in the Battle of Fort Donelson, the Battle of Shiloh, the siege of Corinth, the Vicksburg campaign, the Atlanta campaign, the March to the Sea, and the Carolinas campaign. He was promoted to captain on June 23, 1863, then to major in early 1865. He mustered out on September 19, 1865.
The family lived in Zanesville, Ohio, after the war, and Douglass resumed his work as an editor. By 1870, he owned $6,000 of personal property. They moved to Wilmington, Pennsylvania, in the late 1870s, and then to Topeka, Kansas, in 1884. He died there on April 8, 1890.