Baldwyn. Next Ham and [W. C.] Falkner, each a regiment of cavalry, extending along line of Tallahatchee; pickets north of Holly Springs (Falkner, however, is now at Panola). Brigadier-General Chalmers, commanding Northern Mississippi, headquarters at Panola. [T. W.] Ham, McGirk [John McGuirk], [W. W.] Faulkner, [G. L.] Blythe, and [R. V.] Richardson, and all roving bands are ordered to report to Chalmers. He has one six-gun battery at Panola and one behind the Tallahatchee, near Abbeville. On east side of the river, Cox, Roddey, and a portion of Van Dorn's force are in Hardin, Wayne, and other counties. They is every indication of a raid to be made soon on our lines of communication.

I absolutely need another regiment of cavalry at once for General Dodge; with that furnished me, a good regiment with good horses, I will move from Corinth, La Grange, and this place simultaneously, sweeping round from Corinth to Pontotoc, from La Grange straight down the ridge, with three regiments, throwing one in above Oxford, and cutting the Mississippi Central; the other by Okolona, and perhaps to Columbus, now lightly guarded, cutting that road, while Grierson, with his regiment, would proceed by forced marches to Selma of Meridian. Both Selma and Meridian have few troops. To break the Chunkey River or Pearl River Bridge would be my object. Their rolling stock is reduced and wearing out, as Barney informs me, and they limit trains to 10 miles an hour. They are drawing supplies from Noxubee and other counties of Mississippi, and conscripting relentlessly. As part of this movement, I will send from La Grange or Holly Springs a brigade of infantry and some artillery, and destroy the Tallahatchee Bridge, now being repaired, and break up the car-wheels and axles left there at the time of our withdrawal, which are of vast service to them. I shall also move a force to the left of Panola from this place, so as to keep Chalmers quiet or drive him back toward Grenada.

I dislike to make this movement without more cavalry for Dodge, as he is the most exposed of any point. I therefore urgently request an-other regiment to be sent me at once. If none can be spared from below, I will go on with what I have as soon as I receive your orders.

Your obedient servant,

S. A. HURLBUT,

Major-General.

[Inclosure Number 2. -Extract.]

They (the rebels) are still massing their forces upon Rosecrans, determined to overwhelm him. Their cavalry force is very large, fully 20,000, and they are making every effort to swell it to 25,000, and to crush him by relentless pursuit if the advantage is with them. They are drawing forces to re-enforce Johnston from Richmond, Charleston, Savannah, Mobile, Vicksburg, although few have gone from Vicksburg. The force within supporting distance of Vicksburg he estimates at from 50,000 to 75,000 men.

WASHINGTON, April 9, 1863.

Major General U. S. GRANT, before Vicksburg:

GENERAL: Yours of March 29 is just received.

Your explanation in regard to sending back steamers is satisfactory. I hope you will keep in mind the great importance of not unnecessarily