See these letters written by Secretary of War Judah Benjamin, from the Official Records, Series I, vol 6, pages 758 and 763 --
WAR DEPARTMENT, C. S. A., Richmond, October 29, 1861.
Maj. Gen. MANSFIELD LOVELL, New Orleans:
SIR: Your letter of 18th instant was not received till yesterday, 28th. I telegraphed you to-day that we have no power to receive troops for less than twelve months, but where troops offer themselves specially for local defense they may be accepted in any proportion and for any term, as they are a mere improvised militia, not entitled to pay or subsistence except during actual service. (See act of 21st August, No. 229, of third session.)
WAR DEPARTMENT, C. S. A., Richmond, November 4, 1861.
Major-General BRAGG, Pensacola:
I fully concur in your strictures on the local defense system, but you are mistaken in supposing that the Confederate Government can do anything to prevent it. The difficulty lies with the governors of the States, who are unwilling to trust the common defense to one common head. They therefore refuse arms to men who are willing to enlist unconditionally for the war, and put these arms in the hands of a mere home militia, who are not bound to leave the State. It is a very untoward condition of things, but as we have no arms, and the State authorities will not give us the control of the matter, we are forced to accept from them just what they choose to give. Still worse, they are accepting and arming men for local defense for six or twelve months, and thus breaking up our volunteer regiments that were offering for the war, in order to get from us such arms as we could supply. All this is sad, but I know not how to avoid it. Each governor wants to satisfy his own people, and there are not wanting politicians in each State to encourage the people to raise the cry that they will not consent to be left defenseless at home.
It's no simple matter to try to give a concise answer to most questions about state militia.