Abner Carter (Watson) was born around 1830 in Albemarle County, Virginia. Carter was a slave of John Coles Carter of Albemarle. Carter migrated from Virginia to Missouri in 1852 and owned 126 slaves on multiple farms by the eve of the war. Abner Carter worked on Carter's plantation in Lincoln County, Missouri, where he married Caroline Watson on June 15, 1852. Together, they had three children: William, born April 15, 1854; Sylvia, born May 14, 1857; and Robert, born October 14, 1860.
Carter enlisted at the age of 33 as a private on December 10, 1863, in Troy, Missouri, and mustered in on December 18 at the Benton Barracks in St Louis. His service record describes him as 5 feet, 10 inches tall, with black hair, black eyes, and black complexion. He enlisted for three years and served in Company A of the 65th USCT Infantry Regiment. Carter served about six months. During his service, Carter performed detached duty as a provost guard. He traveled with the 65th USCT to Louisiana in the summer of 1864. On June 29, Carter died at the general hospital in Port Hudson. Army surgeons gave diarrhea as his cause of death.
Following the war, Carter's widow and children continued to live in Missouri. Caroline drew on a pension until her death on September 9, 1869. Nicy Pryor became the guardians of the Carters's minor children and successfully applied for a pension to support them.