How would this have helped? The Confederates had obstructed the Red River and were flooding Bayou Pierre.
Would a week or two of delay have made the outcome better or would it just have brought closer the time at which Smith had to be returned and Grant wanted the campaign given up?
The hypothesis I espoused regarding "Bailey Dams" would have involved building one directly below where the fleet was, and after enough water built up to move the fleet up river aways to where they hit mud again, they could have built another dam to build up more water, and letting the water behind them flow downriver after there ascension and the building of the next dam could conceivably help with the transport of supplies via the river for a
very short time. It would basically be a leap frog movement, risky, time consuming, but a possible counter to the ingenuity of the Confederate Engineers in Shreveport. As for the problem of protecting themselves against a Confederate counter-attack while building up water, Banks could have entrenched wherever the fleets current stop was and send out his Cavalry with Infantry support on raids, or rather probing movements to keep the Confederates off balance, after a short time it wouldn't be Richard Taylor he would be facing, but rather the, rather inept, Kirby Smith, after a switch of Confederate principals, which probably would have happened with no Battle of Mansfield.
As to General Smith's Divisions time limit, I think in the face of progress, (wartime progress is a matter of perspective, and explanation, both areas Banks was half-way competent in), and the support for the Campaign in Washington, I think Banks could have talked his way into keeping them.
The above is short version of my thought process on what I had previously commented lol.
I agree that moving up a single road is a problem, but what was the alternative?
Do you suggest splitting the army and moving it up roads that are distant from each other?
There was a road alongside the Red River, if my memory of the maps isn't mistaken, and there were more than a few smaller, (considering the small size of the main roads, that's admittingly a logistical nightmare), connecting the roads in the area, and if Banks did have guides at his disposal, if they were worth a cent they would know them.
Another possibility would have been to divide his Army with one section going into Texas to use the roads there to head Northward to Marshall, and then strike East to Shreveport, best case scenario at the same time Banks was hitting it from the South, a risky move from their viewpoint to be sure, but given how troops on both sides in the Trans-Mississippi had been accustomed to living off the land in some areas since 1862, and how Eastern Texas was the main breadbasket, with the limited number of
experienced Confederate troops, this would have been possible. It could have conceivably possible with such a move Taylor would have had to divide his already small force to try a fight two groups, and if he had been forced into that position, Mansfield either wouldn't have happened, or there would have a greater chance of Union victory. I admit, if Banks had split his forces, with one wing going into Texas, and the other using the same "Stagecoach Road" it would have been a very risky move, a
bold move, and from they're point of view no guarantee of success, but I think it could have had a possibility of success.
Again, short version of my thought process lol, but its my explanation in the shortest terms I can espouse my thinking.