Born in Warren County, Ohio, to Asahel C. and Meeky (Bobo) Bates, John Calhoun Bates completed his medical study at the Eclectic Medical Institute in Cincinnati, Ohio, in 1850 and then moved to Florida to begin practicing medicine. Around 1855 he married Martha Ann Peeler, and with his wife and her family he later moved to Georgia, where he opened a medical practice and pharmacy. On August 8, 1864, while serving at the City Hall Hospital in Macon, he was arrested by a Confederate lieutenant and imprisoned on unknown charges, then given the choice of serving in the Confederate Army as an acting assistant surgeon or being drafted as a regular soldier. He chose the surgeon position and was sent to the Camp Sumter Military Prison Hospital in Andersonville, where he witnessed atrocities against Union prisoners of war and later testified at the 1865 war crimes trial of Andersonville commanding officer Capt. Henry Wirz. Seeking a new start after the Civil War, the Bates and Peeler families moved to Texas, arriving in Milam County in 1866 and purchasing land. In 1868 Bates bought property in Gatesville and resumed his medical practice there in 1869. He joined local Masonic Lodge #197 as a Master Mason, and his family became active in community social events. He died in 1872 at age 49 and was one of the first people buried in the newly established I.O.O.F. (Odd Fellows) Cemetery.