HEADQUARTERS DEPARTMENT OF THE NORTHWEST,
Milwaukee, Wis., March 28, 1864.

Major General H. W. HALLECK,

Chief of Staff of the Army, Washington, D. C.:

GENERAL; I received yesterday an order from the Adjutant-General's Office assigning the Sixth Minnesota Volunteers, now in this department on duty to the Second Corps, in the Army of the Potomac. I do not write to object to the order, but only to ask a suspension of its execution for a time. My reasons are, that if this regiment be removed from the Minnesota frontier before the new posts are fairly established and the expedition meet the Indians, there will be trouble and excitement on the frontier amongst the inhabitants which may entirely defeat our movements. There seems little doubt of a formidable concentration of the most powerful of the Sioux bands at some point on the upper Missouri. General Sully can only take into the field at most 1,200 men. i have directed Sibley to send him 1,600 men from Minnesota, which will give Sully about 2,800 men, by no means too many if the Indians make battle. Sibley is left with only 700 men on the Minnesota border, and they will be necessary for a time to keep the frontier settlers from abandoning settlements, precipitating themselves in the river towns, and spreading dismay and excitement through the State.

The result will be that the Department in Washington will be overwhelmed with petitions and remonstrances, and our whole military operations, which now promise a final solation of the entire Indian question on the northern plains, be brought to naught. As soon as I possibly can do so (and I am sure, general, the Department will acquit me of andy fault hitherto in forwarding troops to the South) I will send this regiment en route for this corps on the Potomac. Unless I considered it essential to our success I would not think of keeping the regiment a day, and I hope still to send it off very shortly. In this connection, I send you extract from letters received from General Sibly, from which you will perceive the difficulties under which I have labored, and in fact, do still. Unless otherwise directed, I will suspend the execution of the order to the Sixth Minnesota for the present.

I am, general, respectfully, your obedient servant,

JNO, POPE,

Major-General, Commanding.

HEADQUARTERS NORTHWEST INDIAN EXPEDITION,
Saint Louis, Mo., March 28, 1864.

Brigadier General H. H. Sibley,

Saint Paul:

DEAR GENERAL: I am in receipt if your of the 19th. I shall not be in Sioux City much before the 1st of May. I have as much as I can attend to getting my supplies up the river. I have started 50 tons, with an agent, on board the steamer Benton, for Fort Union, where I shall make a depot, and intend to ship next week several hundred tons. To-day I received your letter to General Rope (or rather a copy of it), stating that it is the wish of the Yanktonais and Sissetons that no boats go up the river for the present. This may interfere greatly with my plans, for I am now ordered to establish a post ion the Yellowstone, near the Big Horn. It is impossible for me to operate against the Indians haul the stores necessary for this post. I must depend on the river, and have to take advantage