The data I presented is that found in the National Archives Compiled Service Records which can be accessed through the subscription service, FOLD3. I believe they offer trial subscriptions, see Fold3.com.

As to William Hall, there is no age listed in his file.

William H. Hall, 4th Corporal, Company I, Mississippi Battalion of Infantry,* enlisted August 10, 1861 at Memphis, Tenn. by Lt. Williams for on year, advanced to 3rd Corporal, n.d., recorded absent on the end of year, 1862 muster, "Missing on march from Tippah Creek," recorded present on the next company muster dated June 30, 1863, advanced to 2nd & 1st Corporal, n.ds, on leave January 21, 1865 through February 28, no further records

* This company subsequently became Company A, 1st Battalion Mississippi Sharp Shooters

M269: Compiled Service Records of Confederate Soldiers Who Served in Organizations from the State of Mississippi