I was reviewing the communications or lack thereof between Grant and Rosecrans at Iuka, and I honestly cannot see where Grant ever approved a plan of battle for Iuka. Grants communications to Rosecrans seems to indicate he was hesitant because he was worried about his back door. Rosecrans communications to Grant seem to assume that they were to pitch headlong into the enemy with abandon.
it’s almost like Rosecrans had a different conversation playing in his mind.
In the Papers of US Grant, volume 6, page 64-65, is the communications between Rosecrans and Grant. Rosecrans sends this telegram on Sept 18:
One of my spies in from Beardons, on the Bay Spring road tells of a continuous movement since last friday of forces Eastward. They say Van Dorn is to defend Vicksburg, Breckenridge to make his way to Kentucky, Price to attack luka or go to Tennessee.—If Prices forces are at luka the plan I propose is to move up as close as we can tonight, conceal our movements, Ord to advance from Burnsville, commence the attack, and draw their attention that way, while I move in on the Jacinto & Fulton roads, massing heavily on the Fulton Road, and crushing in their left, cutting off their retreat Eastward. I propose to leave in ten minutes for Jacinto from whence I will dispatch you by line of Videttes to Burnsville. Will await a few minutes to hear from you before I start. What news from Burnsville.'"
Grant replied by telegram:
General Ross' command is at this place. McArthurs Division is north of the road 2 miles to the rear, and Davies' Division South of the road nearby. I sent forward two Regiments of Infantry with Cavalry by the road, north of rail-road towards luka, with instructions for them to Bivouac for the night at a point which was designated, about four miles from here, if not interrupted, and have the Cavalry feel where the enemy are. Before they reached the point of the road (you will see it on the map, the road north of the Rail-road) they met what is supposed to be Armstrongs Cavalry.
The Rebel Cavalry was forced back and I sent instructions then to have them stop for the night where they thought they could safely hold—
In the morning troops will advance from here at 4 1/2 A. M. An anonymous dispatch just received states that Price, Magruder, and Breckenridge have a force of 60.000 between luka and Tupelo.—This I have no doubt is the understanding of Citizens, but I very much doubt their information being correct.
Your reconnoissances prove that there is but little force south of Corinth for a long distance and no great force between Bay- Springs and the rail-road
Make as rapid an advance as you can, and let us do tomorrow all we can—It may be necessary to fall back the day following. I look upon the shewing of a Cavalry force so near us as an indication of a retreat, and they a force to cover it. 15 minutes to 7 P. M.