Further research shows that Robert Monroe Balch was the son of Rev. Thomas B. Balch, and is mentioned by Thomas B. as his son, serving with Bedford Forrest, in Rev. Balch's published wartime letters. the docsouth website has these published letters.

Col. Balch was killed April 6, 1872, in Crittenden County, AR. The Reconstruction sheriff was seizing his brother Charles's farm, Col. Balch objected, shots were fired, and 6 bullets hit the colonel. His remains were brought to Memphis by Charles for burial there in Elmwood Cemetery. Memphis city directories show that Robert was an attorney there in 1860 (born MD, indexed under the last name "Barault") and 1869 (and possibly other years). See the Memphis Avalanche 4-9-72, reprinted in the AR Gazette 4-13-72, for more details. It calls him "Colonel" in the article. Clearly, the AL man was not the major/colonel of Forrest's regiment.

Hope this helps.