Frank W. Douglass was born around 1843 in New York to William Douglass and Harriet White. His father was a millwright who owned $2,000 of real estate and $400 of personal property by 1860. The family moved to Monroe, Pennsylvania, sometime before 1850, and Douglass eventually began working as a millwright, as well. He enlisted in the Union army on August 19, 1862, and mustered in as a sergeant in Company C of the 141st Pennsylvania Infantry later that day.
The regiment took part in the Battles of Fredericksburg, Chancellorsville, and Gettysburg. Douglass was wounded in the head on May 6, 1864, in the Battle of the Wilderness. As he later explained, he was “hit by a Minnie Ball just in the edge of the Hair, over the right eye,” and surgeons “removed Thirty Four pieces of Skull.” The army transferred him to the 21st Veteran Reserve Corps on March 7, 1865, and he was discharged for disability on July 14, 1865. Douglass applied for a federal pension in July 1866 and secured one soon afterward.
Douglass settled in Elmira, New York, after the war. He married Caroline E. Keyser around 1874, and their daughter Florence was born around 1878. Douglass worked as a laborer and tar roofer. The family moved to Elizabeth City, New Jersey, sometime in the late 1880s, and he died in New Jersey on June 24, 1912.