Howard,

The 2nd S.C. Cav. was the cavalry component of Hampton's Legion. Capt. Williams' last letter from Wilmington sounds about right. The 2nd was at Fort Fisher in January of 1865. The regiment is listed on the order of battle for the Surrender at Appomattox Court House as part of Brig. Gen. Martin Gary's Brigade in Fitz Lee's Division

Gary's Brigade, Brig. Gen. Martin V. Gary

7th Georgia, Capt. William H. Burroughs

7th South Carolina, Col. Alexander C. Haskell

Hampton (South Carolina) Legion,(2nd S.C.), Lieut. Col. Robert B. Arnold

24th Virginia, Col. William T. Robbins

Hope this helps

Len