HEADQUARTERS DEPARTMENT OF THE NORTHWEST,
Milwaukee, Wis., August 29, 1863.

Major General H. W. HALLECK,

General-in-Chief, Washington:

GENERAL: I have the honor to transmit, inclosed, a letter to General Sully, specifying the duties he is to perform and the arrangements he is to make for the winter. I propose to keep the Sixth Iowa Cavalry for the winter on the Upper Missouri, as stated in this letter, not so much with a view to the protection of Dakota and the frontier settlements of Iowa, as to prevent the return to Minnesota of the hostile Sioux, lately driven across the Missouri by General Sibley, and to take the field early in the spring to complete the settlement of Indians affairs in Nebraska and the Upper Missouri as far as the mountains. They will serve a good purpose, I hope, and put an end for some time to come to Indian troubles in those regions.

Minnesota I consider secure against any considerable Indian difficulties; indeed, against any at all. The force I shall leave in that State is intended much more to restore confidence to the people than to provide against Indian hostilities. I send you also my letters to General Sibley, specifying in detail the arrangements for his force the winter. All of the troops now in Minnesota except one regiment of infantry, the mounted force I propose to enlist for one year from the mounted regiment whose term of service is about to expire, and the battalion of Hatch's, authorized to be raised by the Secretary of War, will be sent south.

I think it best not to send the Minnesota regiments south before October 1, as they will lose half their effective force by sickness in the sudden transfer to the hot climate of Mississippi during the sickly month of September. They will embark on the 1st of October.

Will you please send me the authority to re-enlist the 500 mounted men for one year, from the mounted regiment now going out of service in Minnesota, and authorize me to designate the officer who shall recruit and command them, with the rank of lieutenant-colonel? There are many officers in the regiment better qualified for the position than any of the field officers belonging to it.

Please send me instructions also in time as to what point in the south the Minnesota regiment shall be sent.

I am, general, respectfully, your obedient servant,

JNO. POPE,

Major-General, Commanding.

[Inclosure.]

HEADQUARTERS DEPARTMENT OF THE NORTHWEST,
Milwaukee, Wis., August 25, 1863.

Brigadier General ALFRED SULLY,

Fort Pierre:

GENERAL: Your dispatch of the 17th is received. It is deeply to be regretted that more rapid progress was not made by the expedition under your command. By referring to my letters to yourself and your predecessor in command, you will find how great was the stress laid upon the necessity of placing yourself in time in position to co-operate with General Sibley, and I am constrained to believe that with energy this much at least could have been accomplished. General Sibley had exactly the same kind of wagons and mules you had (as General Allen, chief quartermaster of the department, himself informs me). He had but little, if any, more wagon transportation in proposition to the strength of