Tenn. Code § 58-1-301
The governor, with the advice and consent of the general assembly, and pursuant to the laws of the United States, shall call the militia, or any portion thereof, into active service at any time that public safety requires it; provided, that the governor is authorized to have enrollment made of all persons of this state subject to military duty or draft into the military service, and is directed, at such time as the necessity seems imminent, to cause each county assessor to make such enrollment of the assessor's respective county, stating the name, address, age, and previous military or naval experience of all persons so enrolled, if any, and to furnish copies of such enrollment to the respective county clerk, and the adjutant general. Each county shall furnish all blank forms and bear all expenses necessary to enrollment of its citizens. The governor shall have the power, in the governor's discretion, to appoint an enrolling board of three (3) members in each county to act in lieu of the county assessor, which board shall make such enrollments as directed at the time by the governor. The governor shall have the power, and is directed, to issue, at the proper time, regulations in detail governing the entry or draft of enrolled citizens into the military service, and their assignments to units.
T.C.A. § 58-1-301