The units you are looking for are the 1st through the 4th Tennessee Enrolled Militia, Farrell's Railroad Battalion- Enrolled Militia and Maginly's and Hepburn's Cavalry Squadrons- Enrolled Militia. These units only real combat was when they were called out during Forrest's big raid on Memphis.
Here's some info on them from Tennesseeans in the Civil War: On September 14, 1863, Major General Stephen A. Hurlbut, Commanding XVI Corps, District of Memphis, issued orders authorizing the organizations of Home Guards under the militia laws of the State, with temporary commissions to be issued by the general commanding the district to the elected officers of the organizations. Authority was given to division commanders to furnish such organizations with arms and ammunition in case of necessity. Organizations so formed were to be used as armed police, and required to put down and repress all robbery, violence, and irregular warfare within their area.
In 1864, references were made in the Official Records to a number of organizations of Enrolled Militia, all in the District of Memphis. Although not called Home Guards, they would seem to have been formed in accordance with this order by General Hurlbut. In addition to the duties set forth above, they seem also to have been subject to call for military service in case of emergency, as on the occasion of General Nathan B. Forrest's raid into the city of Memphis, they were summoned to duty by the firing of a signal gun. Also, in the tables of organization for Federal forces, the Enrolled Militia was included, along with regular army units, in the list and disposition of forces in the District of Memphis.
Reports were found on one battalion and seven regiments of infantry, and two squadrons of cavalry of Enrolled Militia.
On August 25, 1864, Brigadier General Charles W. Dustan, Commanding Tennessee Enrolled Militia, 1st Brigade, District of Memphis, reporting on General Nathan B. Forrest's raid into Memphis, on August 21, 1864, stated that he fired the alarm gun at the Armory, and the men rapidly assembled. He sent the 1st Regiment out on the Hernando Road in support of the forces who were fighting there, and placed the 2nd and 3rd Regiments, by companies, guarding the bridges on Gayoso Bayou from Monroe Street north to the Mississippi River He concluded with this tribute to his men: "The earnestness of purpose and gallant bearing with which each officer and soldier hastened to his post is a guarantee that when the time comes the 2000 stout hearts and strong arms of the members of the First Brigade of Enrolled Militia of the District of Memphis will do their entire duty in the defense of the post." Apparently at this time there were only three regiments.
On December 31, 1864, General Dustan was still in command of the Enrolled Militia which consisted of the following organizations:
1st Tennessee Regiment-Colonel A. P. Curry 2nd Tennessee Regiment-Colonel David Ryan 3rd Tennessee Regiment-Colonel William T. Williamson 4th Tennessee Regiment-Colonel William C. Whitney 1st Tennessee Freedmen-Colonel Edmund R. Wiley 2nd Tennessee Freedmen-Colonel Arthur T. Reeve 3rd Tennessee Freedmen-Colonel Henry Van Horn Railroad Battalion-Major M. J. Farrell Maginly's Cavalry Squadron-Captain R. B. Maginly Hepburn's Cavalry Squadron-Captain W. P. Hepburn
By February 28, 1865, Brigadier General T. Milton Williamson was in command of the Enrolled Militia. Colonel P. H. Heinrich had replaced Colonel William T. Williamson in command of the 3rd Regiment; and Colonel D. G. Chapin had replaced Colonel Wiley in command of the 1st Regiment Freedmen. Colonel Wiley had become colonel of the recently organized 88th U.S. Colored Infantry Regiment. The other organizational commanders were the same as in December.
On April 12, 1865, Major General C. C. Washburn ordered: "The 4th Regiment Enrolled Militia commanded by Colonel W. C. Whitney; the 3rd Regiment commanded by Col6nel Henry Von Heyde; and the Railroad Battalion commanded by Major Farrell, are hereby disbanded. All persons enrolled in either of these regiments who are not Government employees, or in the employ of the City Government, will enroll themselves at once in one of the remaining militia regiments."
When the other regiments were disbanded is not known.
The daily newspaper during Federal control was known as the Memphis Daily Appeal.If your not local, The library here in Memphis has most of it on Microfilm and avialable through interlibrary loan.