HEADQUARTERS DEPARTMENT OF THE MISSOURI,
Saint Louis, Mo., April 6, 1864.

Lieutenant General U. S. GRANT,

Commanding U. S. Armies, Washington, D. C.:

GENERAL: Your letter of the 26th ultimo was handed me by General Hunt.*

I enter warmly into your views of bringing all our available force into the field in the coming campaign. My regret is that I shall not be able to give you much assistance from this department. You will see by the accompanying tri-monthly for March 31, that our force here consists of four regiments U. S. volunteer infantry, six companies colored recruits, one regiment Missouri State Militia infantry, seven regiments U. S. volunteer cavalry, nine regiments Missouri State Militia cavalry, one regiment heavy artillery, not full.

Of these, four regiments of volunteer infantry, one whose term expires in June next, is the prison guard at Alton; two guard this city and the depots and landings here; the remaining one, with the militia infantry, guard the fortified depots and some important railroad bridges in the interior. The existence of secret rebel organizations diffused through the State, a feverish state of publish mind from apprehensions of bushwhacking and rebel raids when the leaves come out, joined [to] the magnitude of our interests in the depots here, render it, in my opinion, inexpedient to withdraw the infantry from those interior posts or greatly to reduce the force now on guard duty in this city. The total available infantry, only three regiments, some 2,000 effective, could only be spared by replacing them with dismounted cavalry. Considering the additional expense and inferior discipline and efficiency for this kind of service, would this be advisable? As to our cavalry, were the Missouri State Militia converted into U. S. Volunteers, or were the organized rebel and guerrilla force in Northern Arkansas driven out, we would have more than sufficient. And when public confidence and tranquillity is once fully established the protecting force could be still further reduced.

But at present it is a matter of high public interest that the inhabitants should feel sufficiently secure to put in their crops. I respectfully recommend, first, that you spare two or three good cavalry regiments to this department; second, that I receive authority to organize such of the Missouri State Militia cavlary as are willing to enlist in the U. S. volunteer or veteran service and to consolidate and use or muster out the remainder as may be seen best; third, if General Steele cannot do it, that this department be permitted to occupy the northern tier of counties in Arkansas and to establish a post at Pocahontas, supplied by steam-boats up White River, having a gun-boat for convoy until we get rid of the rebels there.

These measures will enable me soon to reduce the force needed to get some troops available for outside service. Accompanying is the chief quartermaster's report of transportation, sent with the trimonthly for your information.+

W. S. ROSECRANS,

Major-General.

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*See Part II, p.740.

+Inclosures omitted.

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