Born: 1808 New York
During the Black Hawk War, Demmon was a private in a company of mounted militia commanded by Captain John Dawson. He mustered in from Sangamon County, Illinois, on April 21, 1832 and mustered out on May 28, 1832. In 1860, he lived in Menard County, Illinois, with his wife Eliza and four children.
Ellen M. Whitney, comp., The Black Hawk War, 1831-1832: Illinois Volunteers, vol. 35 of Collections of the Illinois State Historical Library (Springfield: Illinois State Historical Library, 1970), 1:201-205; U.S. Census Office, Eighth Census of the United States (1860), Menard County, IL, 119.