In Booth's: Smith, Jones P., 1st Sergt. Capt. A. C. S. Co. L, Field and Staff, 12th La. Inf. En. Aug. 13,

1861, Camp Moore, La. Roll to Oct. 31, 1861, Present, promoted to Qr. Master Sergt. Aug. 27,

1861. Rolls Nov., 1862, to Aug., 1863, Present.

What does the A.C.S. stand for?