John Carter (John Sellers, Joseph Carter) was born around 1840 in Albemarle County, Virginia. Carter was a slave of John Coles Carter of Albemarle County, Virginia. Carter traced his lineage to Robert "King" Carter, the wealthiest man in colonial Virginia, and he married a descendant of Thomas Jefferson. John Coles Carter and his slaves migrated from Virginia to Missouri in 1852. About 126 slaves worked on his multiple properties by the beginning of the Civil War. John Carter worked as an enslaved farmer on property in Pike County, Missouri. John Carter married Jane Carter, who was also a slave of John Coles Carter, at the Blenheim Plantation on September 19, 1863. The two were married by Isetta Long, the White daughter of John Coles Carter, who stood in for the plantation preacher Thomas Cobb. The Carters did not have any children.

Carter enlisted as a private at the age of 24 on January 18, 1864, in Louisiana, Missouri, and mustered in on March 8 at the Benton Barracks in St. Louis. His service record describes him as 5 feet, 11 inches tall, with black hair, black eyes, and black complexion. He served in Company A of the 68th USCT Infantry Regiment. Carter served for about 6 months. On April 27, Carter and the 68th USCT traveled to Memphis, Tennessee. There, he died in the regimental hospital. Army surgeons gave "hemorrhage of bowels" as his cause of death.

Following the war, Carter's widow, Jane, lived in St Louis and found work washing and ironing. She did not apply for a widow's pension until the early 1880s due to the development of rheumatism later in her life. Due to testimony from Carter's comrade George Scott, a fellow Virginian, she began receiving a pension of $10 a month in 1884.