The troops expected from Saint Louis are not yet heard from, and all that I am bringing from WEST Tennessee are not yet down.

The work of getting through Lake Providence and Bayou Macon, there is but little possibility of proving successful. If the work had been commenced in time, however, there is but little question of the success of the enterprise. The land from Lake Providence and also from Bayou Macon recedes until the lowest interval between the two widens out into a cypress swamp, where Bayou Baxter, which connects the two, is lost. This flat is now filled to the depth of several feet with water, making the work of clearing out the timber exceedingly slow, and rendering it impracticable to make an artificial channel. The Yazoo Pass expedition is a much greater success. Admiral Porter sent in four gunboats, and I sent a fleet of transports, with about 6,000 men. They were to clear the Yazoo and tributaries of all steamboats and embryo gunboats, and, if possible, destroy the railroad bridges at Grenada. The gunboats were to approach as near Haynes' Bluff as possible, and fire signal guns to warn the squadron in the mouth of the Yazoo of their presence.

Last night, about 12 o'clock, Admiral Porter sent me word that the signal agreed upon had been heard.

I am now sending General McPherson, with his army corps and enough other troops to make full 25,000 effective men, to effect a lodgment on the high ground on the east bank of thhere, with his entire force he will move down in transports and by land to the vicinity of Haynes' Bluff. Before moving down, however, below Yazoo City, General McPherson will be made acquainted with the full plan of attack that may then be determined upon, and the time will be so arranged that there will be full co-operation of my entire force. Our movements have evidently served to distract the enemy and make him scatter his heavy guns. His forces are also scattered, but they, with the light artillery, can be got to any one point.

The health of this command is good, and the greatest confidence felt by officers and men. The most ample provision that I ever saw has been made for the comfort of the sick.

The dredging machines brought here by Colonel G. G. Pride work to a charm. After the accident of last night, all work would have had to be suspended until there was a fall of at least 3 feet (the river is still rising), but for these machines. Much credit is due Colonel Pride for his selection of them. But for his personal attention to the selection of them, old and worn-out ones would have been sent, and the result probably would have been that they would have given out before their work was half done.

I am, general, very respectfully, your obedient servant,

U. S. GRANT,

Major-General.

HEADQUARTERS DEPARTMENT OF THE TENNESSEE,
Before Vicksburg,

March 17, 1863.

Major General H. W. HALLECK,

General-in-Chief, Washington, D. C.:

GENERAL: Since the giving way of the dam at the upper end of the canal, work with the dredges has progressed favorably, but all attempts to stop the rush of water into the canal have proved abortive. If required, however, the canal can be made to pass boats of ordinary size in a few days.