John Roberts Teague was born in 1815 in Christian County, Kentucky. Early in his life, his parents brought him to Perry County, Illinois. There he worked as a farmer and married Sarah Jane Harris in 1839. They had three sons: William, Jourdan, and Marion. John recorded $6,000 worth of real estate and $2,500 worth of personal estate in 1860, and by 1870 he had become a merchant in Du Quoin, Illinois. He passed the following year of typhoid fever. William and Jourdan preceded their father in death, and his obituary implies that they died in childhood, likely prior to the war.
John was in his 40s during the Civil War, and there is no record of him having enlisted. The letter to John and his wife sent from his brother-in-law, Jordan Carroll Harris Jr., indicates a warm relationship between the trio. Harris Jr. expresses well wishes for the education of Marion, who was about 16 at the time of the letter.