Hi Joe:
The content of the letter seems genuine enough. It is posted "in the piney woods of South Carolina" near Augusta in February 1865. The author speaks of General Wheeler's fight on "Saturday and Sunday" which took place some 15 miles from Augusta. In my original post this morning, I misdated the Battle of Aiken as having taken place February 8th - it took place over a four day period of February 10th through 13th. February 11th and 12th were a Saturday and Sunday in 1865. Modern state highway maps show Aiken to be 16 miles from Augusta. That part fits.
Battles & Leaders of the Civil War, Volume IV, presents a list of opposing forces at the Battle of Nashville. Bate’s division is under the command of Major-General William B. Bate; Tyler's Brigade is under the command of Brigadier-General T. B. Smith. The 2nd, 10th, 15th, 20th, 30th, and 37th Tennessee Infantry regiments are shown consolidated under Colonel W. M. Shy. This organization table came originally from the Official Records, but I could not quickly find it.
Ezra J. Warner's "Generals in Gray: Lives of the Confederate Commanders" (LSU Press, 1959) states that Robert C. Tyler was promoted to brigadier general on February 23, 1864 while recuperating from his leg amputation. Warner further states that Tyler was posted to West Point, Georgia and was present there during most of the winter of 1864-1865. And he credits Tyler with the defense of a small earthwork at West Point on April 16, 1865.
The next organization table that I found is dated March 26, 1865 "In the Field" and shows Cheatham commanding his own Corps, Bate his own division, and Captain H. Rice commanding Tyler's Brigade. This is the command structure at Smithfield, North Carolina just after the Battle of Bentonville (March 19-21, 1865). (See OR, Series I, Volume XLVII, Part III, page 698.)
The next organization table I found (OR, Series I, Volume XLVII, page 735) is dated March 31, 1865 at Smithfield and shows Cheatham and Bate still in command of their respective corps and division. Tyler's Brigade is still under the command of Captain H. Rice. The 2nd, 10th, 20th, and 37th Tennessee are consolidated under Captain John W. Grayson while the 10th and 15th Tennessee are consolidated under Lieutenant P. Lavin.
The Confederate Army in North Carolina was re-organized at Smithfield on April 9, 1865. Major General Cheatham was placed in command of a division and all of the Tennessee regiments were consolidated into 4 new regiments and placed in a single brigade commanded by Brigadier General Joseph B. Palmer. (See OR, Series I, Volume XLVII, Part I, page 1062.)
That is as much factual information as I have found. It is possible that Brigadier General Robert C. Tyler met up with Cheatham's Corps at Columbus, Georgia in February 1865 and went with them to Augusta. He may even have gone as far as Smithfield, but it does not appear that he commanded Bate's division on the field at Bentonville. Bradley's table of organization for Bentonville shows Cheatham's Corps under General Bate, Bate's Division under the command of Colonel D. L. Kenan (wounded), and Tyler's Brigade under the command of Major W. H. Wilkinson (killed). Dr. Hughes' table of organization is the same. Captain Henry Rice took command when Major Wilkinson was killed. A footnote to the April 9th organization table states that "All the troops of Cheatham's old corps engaged at Bentonville were commanded by Major General William B. Bate."
None of this tells you for sure that the letter to the newspaper editor is not true. I would be inclined to think it is authentic especially if you can trace it to its original published source. In order to be back at West Point, Georgia for his death on April 16, 1865, he would have left the army several weeks prior to that date. Any friendship with General Bragg would have doomed his chances for a place in General Johnston's Confederate Army in North Carolina. My educated guess is that he was turned back at Union Court House in South Carolina at the end of February 1865 when Lee placed Johnston in command.
Hope this all helps!
Hugh