Biographical information on Charles Barnes is limited. On 17 November 1841, Barnes, of Leicester, Massachusetts, married Mary Peabody Foster (b. 16 January 1814), daughter of Moses and Sarah Foster. A son, Charles Henry, was born to Charles and Mary on 7 December 1849 in Leicester. In addition, they had a daughter, Sarah Foster Barnes.

Charles Barnes was employed by Sawyer, Phelps & Company, a machinery manufacturer in North Andover, Massachusetts. In 1834, he and a fellow employee purchased the business that became Barnes, Gilbert & Company. Barnes left the business in 1835, joining the Ballardville Manufacturing Company, a woolen manufacturer. He returned to the machinery business in 1838, only to rejoin Ballardville in 1841, serving as an agent. During the period of these papers, Barnes was situated in Webster, Massachusetts.