I have a database of transcribed articles from mostly Southern newspapers at http://www.uttyler.edu/vbetts/newspaper_titles.htm. It is not even close to being comprehensive because I focused on the homefront, not the military and not political issues. But it is free and it is searchable, and perhaps it will be helpful until something better comes along. It has taken years to compile.
That said, there are a number of articles about Warren Adams, who appears to have been the main private mail carrier from the east side of the Mississippi to the Houston area. No map, though, and no details. These are just in the order that I pulled them up.
GALVESTON WEEKLY NEWS, March 16, 1864, p. 2, c. 1
"Our next army mail" will leave in charge of Mr. Adams about the 25th inst. He will take money or valuable entrusted to his care, on commission. Letters to be taken by him should be forwarded to us without delay, accompanied with $5 each.
GALVESTON WEEKLY NEWS, June 29, 1864, p. 2, c. 1
The Army Mail.—We are requested by Mr. Warren Adams to state that on account of the heavy discount on the old currency, and for the reason that he now brings back a heavy mail without a charge, his charge per letter for his next mail will be $10. His expenses will now be quite double in the old currency what they have been. Charge for taking and delivering money 10 per cent. He will leave on the fourth of July.
There will be ample time for answers to be written, to be brought by Mr. Adams, on his return; and those who wish answers should direct them to be sent AT ONCE to "Montgomery, Ala., care of 'Advertiser,'" or to "Mobile Ala., care of 'Register and Advertiser,'" and they will be brought FREE OF CHARGE. On his last trip Mr. Adams brought back just about as many letters as he carried over.
GALVESTON WEEKLY NEWS, September 14, 1864, p. 2, c. 1
We have received a note from the Post Office Department, requesting us to discontinue our private express. The letter says: "Letters mailed at any point west of the Mississippi river, prepaid forty cents and endorsed express mail via Shreveport, Louisiana, will go across the river with as much certainty as if sent by private hands and at an expense that does not tax so heavily the soldier or his family.
GALVESTON WEEKLY NEWS, November 30, 1864, p. 2, c. 2
We learn from Mr. Warren Adams that the Government mail arrangements for crossing the Mississippi are entirely broken up. A very large amount of mail matter, letters &c., has accumulated at Brandon, Mississippi—several cart loads—and there is no prospect whatever that it will ever be sent to its destination. This mail matter has been accumulating there for the last two months, and we presume, letters sent from this side have in like manner been accumulating at Shreveport or Monroe during the same time. Those of our citizens, therefore, who have depended on the Government mail will understand that their letters have not gone forward, and are not likely to go forward.
[HOUSTON] TRI-WEEKLY TELEGRAPH, August 7, 1863, p. 2, c. 1
We regret to say that there is no way now of sending letters across the Mississippi.
[HOUSTON] TRI-WEEKLY TELEGRAPH, September 30, 1863, p. 2, c. 1
We had the pleasure of meeting Capt. Ashby, of the Rangers, yesterday. He brought through about 700 letters from Bragg's army, most of which he mailed at this place. Among his letters, we have to thank him for one from our special correspondent in the Rangers, R. F. B., whose letters are always so welcome to our readers.
GALVESTON WEEKLY NEWS, October 7, 1863, p. 2, c. 7
Notice to those Desiring to Send
Letters Beyond the Mississippi.
The undersigned, having for some time contemplated establishing a regular courier line to connect with the nearest Confederate mail lines on this and on the other side of the Mississippi, have determined to make their first and second trips entirely through from this city to Richmond and back, and will leave Houston on the first trip on the 15th instant, and on the second trip on the 1st of November. They will take all letters entrusted to their care directed to soldiers and others, at two dollars per letter, and will deliver all letters directed to soldiers to the headquarters of the army to which they belong, but those directed to Gen. Lee's army will be deposited in the P. O. of Richmond. Letters to persons not in the army will be mailed in the nearest Post office on the other side of the Miss., so as to secure their safe transmission. They will also bring letters in return.
J. R. Van Liew.
W. Adams.
GALVESTON WEEKLY NEWS, October 14, 1863, p. 2, c. 1
The Postmaster General advertises that all official communications, letters, newspapers, &c., intended for the east side of the Mississippi, should be addressed to their proper destination, via Shreveport, La., care of the postmaster at that place.
GALVESTON WEEKLY NEWS, December 30, 1863, p. 1, c. 3
Private Express Notice.—We are authorized to state that Mr. Warren Adams will leave this city again, to take the army mail East of the Mississippi, on the 10th of January. Those wishing to send letters to their friends in the army may rely upon their being delivered if in Bragg's army at his headquarters, but if to soldiers elsewhere, or to those not in the army, then they will be deposited in the post office at Meridian, Miss., where they will be taken by the regular mail without delay. Correspondents wishing answers will inform their friends to have their answers left at Meridian, to the care of Mr. W. Adams, at any time up to the 8th of February, and they will be brought by him on his return at one dollar each. Money letters will be taken by special contract and receipted for, provided the parties are within each, so as not to delay his return. All letters to be taken by him should be directed, under cover, to the care of the Telegraph or News offices of this city, with the usual fee of two dollars enclosed, and they will be properly assorted and registered.
MOBILE REGISTER AND ADVERTISER, July 21, 1864, p. 1, c. 5
Mr. Warren Adams, the indefatigable and successful letter carrier, arrived here yesterday, having left Houston, Texas, on the evening of the 4th inst., bringing with him a large mail for the soldiers in the armies of Georgia and Virginia. He brought intelligence of an encouraging character concerning operations west of the Mississippi. He left last evening with the hope of going through to the army of Gen. Johnston, and will return in about ten days. He is a careful and a responsible man, and letters entrusted to his care will be punctually and faithfully delivered.
MOBILE REGISTER AND ADVERTISER, July 21, 1864, p. 2, c. 6
Letters for Trans-Mississippi
Will be taken by Warren Adams, at Five Dollars, with postage paid, to the 31st of July inst. Send to the care of Advertiser and Register.
References, H. O. Brewer & Co., W. G. Clark.
GALVESTON WEEKLY NEWS, February 8, 1865, p. 2, c. 2
Army Mail.—An army mail will leave for Richmond, direct, on or about the 15 February. Letters must be prepaid 40 cents and Carrier's fee 50 cents specie. Address care News Office.
GALVESTON WEEKLY NEWS, March 22, 1865, p. 4, c. 1
Mr. Warren Adams returned from Richmond, Va., on Wednesday. We are indebted to him for files of Southern papers, which, though not late, are such as we have not before seen, and from them we shall be able to give our readers many interesting extracts. He brought back some letters, but not as many as usual, on account of the general derangement of the mails. These letters have been mailed to their proper destinations. He left Brandon on the 2d inst., and crossed the Mississippi on the 5th, but was delayed at the Neches, where he had to leave his horse and hire a boat. He was also delayed by impassable streams on the other side, but encountered no other trouble. He met with no Yankees anywhere. . . .
--I'll see what I can find on Warren Adams in the military records next.
Vicki Betts