" As it became evident that the contest would be long and severe, better measures of preparation were enacted. I was authorized to call out and place in the military service for three years, unless the war should sooner end, all white men residents of the Confederate States between the ages of eighteen and thirty-five years, and to continue those already in the field until three years from the date of their enlistment. But those under eighteen years and over thirty-five were required to remain ninety days. "

― Jefferson Davis , The Rise and Fall of the Confederate Government