I have been following this thread with interest. Mathew N. WALDROP was held at Fort Delaware on two different occasions. Your original query opined that he had died in 1864.
The Fort Delaware Society database contains a brief entry for M. N. WALDROP/WALDRUP, Company D, 13th Alabama Infantry showing he was a POW at Fort Delaware, hospitalized from 22 SEPT to 26 SEP 1864, and giving his date of death as 30 SEP 1864. The sources for this "information" are given as NARA Tapes 40 & 47. These are microfilm rolls from the National Archives pertaining to Fort Delaware only and often this information did not get picked up and placed in the Compiled Military Service Records. However, the 1912 War Department "Register" listing Confederate dead from Fort Delaware does not confirm his death at Fort Delaware.
I examined the CMSR in detail via footnote.com and came to the same conclusion that Alan did. Mathew N. WALDROP was a POW at Fort Delaware on two separate occasions. Captured at South Mountain on 15 SEP 1862, he was sent to Fort Delaware, paroled there on 2 OCT 1862 and delivered to Confederate authorities at Aiken's Landing on the James River as a paroled prisoner of war on 6 OCT 1862. He was declared exchanged on 10 NOV 1862 and returned to duty.
Mathew was captured a second time at Gettysburg. His name (rank & unit) appeared on a composite list of "sick and wounded Confederates in the hospitals in and about Gettysburg after the battle of July 1, 2, and 3, 1863" with the notation that he was transferred to the Provost Marshal. An undated roll at Fort McHenry shows he was captured 4 JUL 63 (his name, rank and unit of service taken down on that date) and sent to Fort Delaware. His arrival at Fort Delaware is dated in the time window 7/12 JUL 1863. NARA Tape 47 shows that he was admitted to the Fort Delaware Post & Prison Hospital on 22 SEP 1864 and discharged back to barracks on 26 SEP 1864. He was then paroled at Fort Delaware on 28 SEP 1864, sent away on 30 SEP 1864, and delivered to Confederate authorities at Varina, Virginia (near Aiken's Landing) on 5 OCT 1864. He was examined in the Receiving & Wayside Hospital (General Hospital No. 9) at Richmond on 6 OCT 1864, judged to be fit for duty and sent to Camp Lee on the outskirts of Richmond to await an exchange declaration. He applied for a furlough on 9 OCT 1864, was issued clothing on 11 OCT 1864, and shown on the Company D muster roll to be present for duty on 31 OCT 1864. There are no other records in his file other than a final parole dated 22 MAY 1865 at Talladega, Alabama.
The CMSR shows that he was enrolled on 6 JUL 1861 in Randolph County, Alabama by Captain James Aiken commanding a company of volunteers that became Company D, 13th Alabama Infantry. Captain Aiken became Colonel of the regiment.
It would appear that he was granted a furlough in the fall of 1864 after he rejoined his company and that he was at home when the war came to an end. As an absentee from his unit which was surrendered in Virginia on 9 APR 1865, he reported into the Provost Marshal at Talladega, Alabama to be accounted for and released on parole.
I will be correcting the Fort Delaware Society database entry to reflect the information found in the Compiled Military Service Records. When you know more about Mathew N. WALDROP, the Society would appreciate hearing from you!