In January 1864 to help with planning the spring campaign, General Banks asked his chief engineer to prepare a map and a report. Below I copied the report...
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OFFICE OF THE CHIEF ENGINEER, DEPT. OF THE GULF,
New Orleans, La., January 22, 1864.
Major-General BANKS,
Commanding Department of the Gulf:
GENERAL: I have the honor to submit the following information concerning the routes from the Mississippi River to the interior of Texas: Brashear City to Alexandria, 174 miles; Brashear City to Shreveport, 344 miles; Simsport to Alexandria, 70 miles; Natchez to Alexandria, via Harrisonburg, 80 miles; Natchez to Natchitoches, 120 miles; Vicksburg to Shreveport, 148 miles; Little Rock to Shreveport,225 miles; Fort Smith to Shreveport, 300 miles; Alexandria to Shreveport, 170 miles; Alexandria to Houston, 270 miles; Shreveport to Houston, 295 miles.
The water via Red River commences falling about the 1st of May, and the navigation of the river for the most of our gun-boats and transports is not reliable after that time. The months of March and April are unfavorable for operations in Northern and Eastern Texas, owing to the high stage of water in the Sabine, Neches, and Trinity Rivers, and their tributaries, and the overflows to which their banks are subject. The concentration of all the forces available for operations west of the Mississippi in the vicinity of Shreveport requires that the line of supply with the Mississippi be kept you. It would not be practicable to abandon the base with so large a force, with a line of operations of 300 miles, through a country occupied by the enemy, to be overcome before communication could possibly be effected with points held by us on the coast.
The water communication to Alexandria cannot be depended on after the 1st of May, and it would be necessary to depend on the road from Natchez, a distance of 80 miles, or possibly from Harrisonburg, a distance of 50 miles. Boats of very light draught, say 3 or 3 1/2 feet of water, may go to Alexandria during low water at ordinary seasons, but the large majority of our boats and gun-boats are of greater draught than this. The most reliable routes would be by the railroad from Vicksburg to Shreveport. The track is now laid from Vicksburg to Monroe. The road is graded from Monroe to Shreveport, and mostly bridged; the distance is 96 miles. There is a good wagon road from Monroe to Shreveport, crossing the Washita River and other streams.
It would require at least three months to rebuild this railroad, which is indispensable to the supply of an army in Northeastern Texas. To insure success and permanent results to the operations of a force to operate against Texas, or, rather, against the rebel forces west of the Mississippi, it is essential that the forces available for this purpose, viz, those now west of the Mississippi, and any additional forces that may be assigned, should be placed under the command of a single general. The rebel forces west of the Mississippi have a single head, and so should the forces operating against them. Preparations should be made to establish a line of supply, independent of he water-courses; otherwise, by the time the forces are concentrated and ready to move forward, they, will be compelled to halt until a new line of supply is established thus giving the enemy a breathing spell and an opportunity to harass our communication with their mounted troops.
It is of vital importance, in operation of this kind, where the distances traversed are so great, that there should be no delays, for our main security against raids on our communications consists in keeping the enemy so well occupied in taking care of himself that he will have no time or opportunity to trouble us. Hence the importance of thorough preparation and perfect concert of action among the different corps. Suppose it is determined to concentrate the forces near Shreveport, preliminary to a movement into Texas. This point is the principal depot of the enemy west of the Mississippi. There are some machine-shops and dock-yards there and the place is fortified by a line of works with a radius of 2 or 3 miles. The position is a strong one, being on a bluff and commanding the eastern bank. The point suggests itself at once as a proper one for such a concentration.
The most direct and only reliable line of supply to this point would be the road from Vicksburg to Shreveport, railroad as far as Monroe, 52 miles, and a graded road the rest of the way, 96 miles. It would be necessary to put the road in running order and procure materials for completing the road. The security of this road requires that the enemy be driven out of Northern Louisiana and Arkansas. This line could be held much more easily than the Red River, which is very narrow and crooked and which has, in many places, high bluff banks where field artillery could be placed to enfilade the channel and have no fear of gun-boats. Such a point is Grand Ecore, where the bluff is 120 feet high. This point, I have been informed by spies, is fortified. Concerning the mode of uniting the forces near Shreveport I will mention no details, as it will depend much on the enemy's movements and the character of the routes in Southern Arkansas, which I have not had time to examine fully; our forces there have, doubtless, the information necessary to arrange this matter.
These movements, however, should be so arranged as to drive the enemy out of Arkansas and Northern Louisiana. I anticipate no danger from any large force moving on New Orleans from Texas. In case of this movement our forces would then immediately come in on the rear of this force and cut it off. The enemy will, I think, be unable to interfere seriously with our concentration of troops, and will then mass his whole force, except that at Galveston, near Shreveport, when he will fight or retire on the line he may select.
Suppose our forces to be united at Shreveport, which could probably be effected during the season of high water, and that arrangements have been perfected to supply the army by the road from Vicksburg via Monroe, Arkansas and Louisiana clear of rebels, and the enemy in retreat. I assume that he will do this, as our force should be much larger, than this and that he will continue to retreat, knowing that we will be weakened thereby, while he can select a defensive position far from our base. Whatever way he takes we must follow and expect to have our path disputed at every point, as he will be driven to desperate efforts. The numerous streams with high banks will afford him a favorable opportunity to retard our progress and effect a secure retreat to any point he may select. Our subsequent movements cannot well be foreseen. It does not seem probable that the enemy will return to Houston unless his force is large and he should propose to draw us into a trap.
It is more probable that he will retire farther west and use his cavalry to harass our flanks and rear, a species of war peculiarly adapted to Central and Western Texas. We should then be prepared for a most active campaign, and our force of cavalry should be specially large and efficient. Again, recurring to the line of supply, it will be seen that the Vicksburg and Shreveport road extends to Marshall, where there is an interval of 40 miles to Henderson, whence the road is completed to Galveston. The road from Marshall to Henderson, however, is graded, and could be completed in a short time. In case the enemy should abandon the coast this road will fall into our possession, and supplies could be obtained from two directions. Our colored troops, who are especially qualified for fighting guerrillas, could be usefully employed in guarding the entire line of this road from Vicksburg to Galveston. Texas is said to be full of blacks, who will be a valuable auxiliary in our operations in that State.
The campaign above sketched out would, I believe be a long one. Much preparation and labor will be required to insure the army against vexatious delays, which permit the enemy constantly to elude us. I should estimate, roughly that it would require until some time in May to effect the union of forces and be prepared with transportation for a movement into the interior. This would be about the commencement of the season most favorable for active operations in Texas. I suppose by that time wagon trains will be provided to haul supplies from Monroe to Shreveport, that the railroad will be in running order to Monroe, and the work of completing the road well under way. The time required for subsequent operations cannot well be estimated. It is highly probable that the rebel army will suffer greatly from destruction, an easy matter in an active campaign. The Arkansas will probably leave in the greatest numbers. Should their army, however, hold together well they will be able to prolong the contest some time.
The results of this campaign will be very great. As long as we are able to keep the enemy actively engaged in Texas, Louisiana and Arkansas, will be safe, and the process of reconstruction can be carried on without interruption; and should those States establish loyal State government, there can be no doubt that desertions would be very numerous. This plan of operations has the advantage over that of operating from the coast of Texas. It also has the advantage of enabling us to bring a much larger force of cavalry into the field. It is,however, a much more difficult plan to execute, requires much more time, and is much more uncertain as to the time it will require to accomplish any of the objects undertaken.
The movement by the coast of Texas possesses the great advantage of enabling us to deceive the enemy as to our intentions, which is not the case with the other plan. Our troops and supplies can be quickly moved by steamer to any point on the coast. Landings can be threatened at different points and the enemy kept in ignorance of our intentions. We now hold the harbor of Matagorda, the best on the coast, next to Galveston. We have a secure point for the debarkation of troops and supplies. The distance by land to Houston is 150 miles, over good roads, three in number, one via Texana and Wharton, one via Matagorda and Columbia, and the third along the beach to the mouth of Brazos River.
Very little baggage need be required on this march as the point of supply can be transferred to Brazos River, and San Luis Pass in succession. A much less force would be required for this operation than the other. The rebel forces now in Arkansas will remain there as long as our force is opposed to them, and we would only have to meet the force in lower Texas.
To divert and draw off this force as much as possible, the following plan could be adopted; Every preparation should be made for debarking the troops at Matagorda and transferring them to the mainland. The troops intended to be sent should be designated and collected at New Orleans so as to go aboard at a moment's notice. The steamers should be got ready and the troops assigned; all the heavy material, artillery and horses, be placed on board the light-draught vessels, leaving only men and light stores to be lightened. A demonstration of gun-boats and troops on transports could them be made at Alexandria in moderate force, the effect of which would be to withdraw the enemy from lower Texas. This having been effected the troops at New Orleans should be sent with all dispatch to Texas the forces marched to Houston without delay, and Galveston be invested and the garrison captured, unless they hurriedly evacuated. This would give us entire control of the coast of Texas in a comparatively short time. For subsequent operations we would not be as well prepared as we would be at Shreveport, with our forces concentrated. The object we started out with would have been accomplished, viz, the possession of the coast. The object proposed by the movement via Shreveport is much greater than the other, and hence requires more time and means. That direct object is no less than the complete destruction or scattering of the rebel army west of the Mississippi, and it will be impracticable to stop short of this result. To attempt simply to hold Shreveport as a post, would subject us to continual annoyance as long as an organized force remained in Texas. They would make continual raids on our flanks and rear, and our resources would be gradually frittered away. The rebel army must be pursued until it is broken up, and then we can occupy the country and restore order.
I have written the above in some haste, necessarily, and have endeavored to make my ideas clear, though perhaps they may be somewhat boldly expressed. A strict comparison between the two plans of operation can hardly be made, as their objects are different. The only question is, which can be most successfully carried out. The results promised by the first plan are much more satisfactory, and they include those of the second. I do not believe, with some, in the impossibility of long land marches with a large force, but I am fully aware of the difficulties to be overcome and the uncertainty of foreseeing results.
I am, general, very respectfully, your obedient servant,
D. C. HOUSTON,
Major, A. D. C., and Chief Engineer, Dept. of the Gulf.