Douglas was born on January 25, 1843 as a slave on a plantation in Fairfield County, South Carolina. In 1862, during the US Civil War, he went to the front lines as a body servant for his masters' son, in the Confederate Army. Douglas became free by 1864 and moved north as a blacksmith and bummer (a nickname for foragers) of Maj. Gen. William Tecumseh Sherman of the Union Army.
In 1866, Douglas settled in what was to become Fairview, Bergen County, New Jersey. He married a local resident, with whom he had a son and daughter. He ran his own blacksmithing business into his 90s. He lived there until he died on March 8, 1950.
He is interred in Hackensack Cemetery (#4738, Sec 16, Row 12).
- "NJ Black History Month: Remembering state's last Civil War soldier". Retrieved 12 February 2018.
- "This Black History Month, Fairview remembers its last Civil War veteran". Retrieved 12 February 2018.
- J.H, Segars (23 September 2010). Black Confederates. Pelican Publishing. ISBN 9781455601233. Retrieved 12 February 2018 – via Google Books.
- "Simon Douglass (1843-1950) - Find A Grave..." www.findagrave.com. Retrieved 12 February 2018.
- "Letter: Some clarity needed on Simon Douglas story". North Jersey.com. Retrieved 12 February 2018.