General Grant’s left and centre were at last accounts approaching the Yalabusha, near Grenada, and the railroad to his rear, by which he drew his supplies, was reported to be seriously damaged.  This may disconcert him somewhat, but only makes more important our line of operations.  At the Yalabusha General Grant may encounter the army of General Pemberton, the same which refused him battle on the line of the Tallahatchie, which was strongly fortified; but, as he will not have time to fortify it, he will hardly stand there; and, in that event, General Grant will immediately advance down the high ridge between the Big Black and Yazoo, and will expect to meet us on the Yazoo and receive from us the supplies which he needs, and which he knows we carry along.  Parts of this general plan are to cooperate with the naval squadron in the reduction of Vicksburg; to secure possession of the land lying between the Yazoo and Big Black; and to act in concert with General Grant against Pemberton’s forces, supposed to have Jackson, Mississippi, as a point of concentration.  Vicksburg is doubtless very strongly fortified, both against the river and land approaches.  Already the gunboats have secured the Yazoo up for twenty-three miles, to a fort on the Yazoo at Haines’s Bluff, giving us a choice for a landing-place at some point up the Yazoo below this fort, or on the island which lies between Vicksburg and the present mouth of the Yazoo. (See map [b, c, d], Johnson’s plantation.)

But, before any actual collision with the enemy, I purpose, after our whole land force is rendezvoused at Gaines’s Landing, Arkansas, to proceed in order to Milliken’s Bend (a), and there dispatch a brigade, without wagons or any incumbrances whatever, to the Vicksburg & Shreveport Railroad (at h and k), to destroy that effectually, and to cut off that fruitful avenue of supply; then to proceed to the mouth of the Yazoo, and, after possessing ourselves of the latest and most authentic information from naval officers now there, to land our whole force on the Mississippi side, and then to reach the point where the Vicksburg & Jackson Railroad crosses the Big Black (f); after which to attack Vicksburg by land, while the gun-boats assail it by water.  It may be necessary (looking to Grant’s approach), before attacking Vicksburg, to reduce the battery at Haine’s Bluff first, so as to enable some of the lighter gunboats and transports to ascend the Yazoo and communicate with General Grant.  The detailed manner of accomplishing all these results will be communicated in due season, and these general points are only made known at this time, that commanders may study the maps, and also that in the event of non-receipt of orders all may act in perfect concert by following the general movement, unless specially detached.

You all now have the same map, so that no mistakes or confusion need result from different names of localities.  All possible preparations as to wagons, provisions, axes, and intrenching-tools, should be made in advance, so that when we do land there will be no want of them.  When we begin to act on shore, we must do the work quickly and effectually.  The gunboats under Admiral Porter will do their full share, and I feel every assurance that the army will not fall short in its work.