CAIRO, ILL., October 1, 1862.

Thus far I had written when General Steele called on me and showed me an order form General Curtis to him requiring a large portion of his army to move via Sulphur Springs and Pilot Knob, Mo. Believing that we at Helena had a better knowledge of the disposition of the enemy and his strength in Arkansas than any one at Saint Louis, I am confident the execution of General Curtis' order will be attended with disaster. In this opinion General Steele concurs. You have previously ordered him to communicate with you direct, and from this circumstance he inferred he would received orders from you direct. I started immediately for this point in order to communicate with you, having also some later intelligence than that contained in the preceding part of this letter, which I embodied in the dispatch I sent you to-day, of which the following is a copy:

CAIRO, ILL., October 1, 1862.

Major-General HALLECK,

Washington City, D. C.:

General Curtis has ordered General Steele to go to Pilot Knob via Sulphur Springs, Mo., and take with him more than one-half the infantry and more than one-half the field pieces, mountain howitzers excepted. Reliable information that the enemy has 25,000 to 30,000 men and from forty-two to fifty pieces of artillery near the center of Arkansas; principal part within 30 miles of Little Rock. Regiments from Texas just arrived. Have force and arsenal at Arkadelphia, 60 miles southwesterly from Little Rock; make guns, gunpowder, and percussion caps.

No large rebel force on boarders of Missouri, therefore no immediate danger of invasion. Enemy threatens to attack Helena. fort Curtis not complete, and no account when completed, as it is commanded by two hills in neighborhood. If Steele and troops ordered shall leave Helena, residue must remain idle or be withdrawn; those left insufficient to move into Mississippi or Arkansas River and arsenal at Arkadelphia destroyed. Present more favorable time to travel and secure supplies in the country than at later day. Supplies of cattle taken from Arkansas and Texas east of Mississippi River. Hope you will countermand General Curtis' order and order General Steele to move on enemy in Arkansas. Army pleased with Steele. Have been sick-am sick, and have come to telegraph. Await your answer. Boats insufficient for General Steele to move before I return if dispatched immediately.

JNO. S. PHELPS,

Military Governor of Arkansas.

The execution of this order of General Curtis will be a virtual abandonment of Arkansas till an army can move into the State of Missouri. It too much resembles the movement of last autumn into Southwest Missouri under General Fremont. Our army has invoked the Union men on the line of its march to rally to the support of the Union, and then coolly abandons them to the tender mercies of a Hindman and his rebel force. Such a course on the part of our rulers has already been too often done to bear a repetition unless there should be some great overruling military necessity.

I am, with respect, your obedient servant,

JNO. S. PHELPS,

Military Governor of Arkansas.

HEADQUARTERS DEPARTMENT OF THE NORTHWEST, Saint Paul, Minn., September 28, 1862.

Colonel H. H. SIBLEY,

Commanding Sioux Expedition:

COLONEL: Your dispatch giving me an account of your skirmish with the Indians was sent me by the Governor of Minnesota. Whilst