You should be able to find this in Holly Springs. On June 2, 1865, E. L. Richmond was issued a marriage certificate in Marshall County to marry Tranquilla McRevere. In his military record, E. L. Richmond states that he was born in Tennessee about 1838 and not married. Being single when the war began, this may have been his first marriage. Richmond came from a fairly well-to-do family of Robertson County TN. In 1860 the head of household, W. C. Richmond, owned eighteen slaves.
Cross Plains isn't far from the Kentucky state line. Captain Richmond's service record with McGuirk's 3rd Missisippi Cavalry includes a physical description, which lists his occupation as school teacher. Age and birthplace appears there as well. Evidently Richmond left home shortly before the war began to teach a school in Mississippi.
There are two service files for this man. On May 27, 1861, Capt. John McGuirk enrolled Edward L. Richmond to serve in the "Mississippi Rangers", which became Co. "B", 17th Mississippi Regiment. While in Virginia Richmond became a member of the regimental color guard, but was discharged at Charlottesville VA for tuberculosis.
On April 25, 1863, Edward L. Richmond organized a mounted company at Oxford MS. Officers and men entered state service for one year on May 11, 1863. Richmond's company reorganized for Confederate service at Tupelo MS on May 3, 1864. The entire brigade (which wasn't very large) was dismounted in July 1864 and sent by rail to Atlanta. Gholson's men suffered heavy losses in fruitless attacks on Lickskillet Road, July 28, 1864. The brigade was remounted for service with Hood's army after Atlanta was evacuated.
He was never captured, surrendering with survivors of his command at Gainesville AL, May 12, 1865. His company letter designation was always given as "E" up until Gholson's brigade was consolidated near the end of the war. The article you cited probably mistook the cursive letter "E" for a "C."