Smith and other reliable sources, of the passage of the Arkansas River by various parties of the enemy's cavalry, in aggregate larger than my present force in any one district;* all making their way northward by various routes, and in bodies of a size to suit circumstances. The horses of my cavalry are exhausted with constant scouting, fighting, and watchfulness. The evident intention of the enemy is to concentrate at some point within my lines, and strike a blow before troops can be concentrated from a distance to oppose them. My most reliable district commanders are representing constantly the danger to be apprehended, but I am powerless to make disposition without troops. In three days the city of Saint Louis will be without a guard for its immense depots of army material, supplies, hospitals provisions of war, and except two regiments of the city militia, which I have this morning taken the responsibility of ordering out for 100 days.

I desire respectfully to lay these facts before the honorable Secretary of War. The object of this is not to complain of the ordering of troops from this department to General Canby, or whose wants I am informed; but as it would take too long to communicate with General Canby and get his orders to meet the present emergency, I therefore request that such orders and instructions may be given as to meet it. Beg also to call attention to the fact I already communicated, of the existence of a powerful armed secret society in the department which only awaits opportunity to co-operate with the rebels and spread arson and murder over the State.

W. S. ROSECRANS,

Major-General.

HEADQUARTERS DEPARTMENT OF THE MISSOURI,
Saint Louis, May 29, 1864

Major General E. R. S. CANBY,

Commanding West Miss., Div., Hdqrs. Natchez, Miss.:

GENERAL: That which I earnestly recommended in a letter to the War Department on the 10th of March, ultimo, and which was begun by ordering you to the command of Banks' and Steele's departments, has at last been completed by General Orders, Numbers 203, War Department, by which the West Mississippi Division is created, and this department made a portion thereof. I telegraphed on the 27th informing you of this fact, and promising a copy of our last tri-monthly, by an inspection of which you will see the available force, its character and how it is scattered over the State. You will have learned from General Steele that a large body of rebel cavalry has crossed the Arkansas, either to operate on his communications or make a raid into this department. The consequence of a raid here, with a formidable and well-organized cavalry force, cannot but be very serious, considering the feeble and widely scattered forces with which we would have to make head against it.

We have all our grand depots, our railroad bridges, and lines of communication to guard, while the enemy concentrated and organized, would be at liberty to strike any point they choose. It must not be overlooked that we owe much to the loyal people of this State,

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*As received by the Adjutant-General the words "in any one district" were omitted. See Halleck to Rosecrans, and reply, May 30, pp. 123, 124.

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