My ancestor E.P. Gower has been shown:
E. P. Gower TN Co.D. 12th Cons. Tennessee Inf.[Captain T.W. Williams Company Under CSA General Leonidas Polk.] , Joined 7 Dec 1861 at Newbern, TN by T.F.Williamson for 1 year.
Transferred Apr 1862 to Capt. L.M.Williams 22nd Rgt. T.V.,
Shown on a report of absentees without leave from 1st Brigade, 1st Division, 1st Corps, Army of the Mississippi dated 24 June 1862- deserted,
On Muster roll 18 May 1863 Co.D. 12th Cons. Tenn. Inf.

Recently I found a record on Ancestry.com that E.P. had been taken prisoner 14 Mar 1862 in Newbern, TN which I didn't know. And the record said that he was part of the 26th N.C.M , a musician, and was being held at Fort Columbia, N G Harbor, An or Cntinen(writing was bad)
Anyone know what the N.C.M means?
Or where Fort Coplumbia was?
Or what NG Harbor means?

Thanks in advance for any help
Jerry