WARRENSBURG, June 21, 1864.

Major O. D. GREENE,

Assistant Adjutant-General:

I have the honor to report that, in obedience to the orders of the major-general commanding, received at 9 o'clock last night, to concentrate the cavalry in my command, I have ordered the Second Colorado the rendezvous at Pleasant Hill, except one company to remain at Kansas City to guard the stores; seven companies of the First Missouri State Militia on duty scouting in La Fayette and Saline Counties, at Mound Prairie Church, near Tabo, between this station and Lexington, leaving one company to guard the stores at Lexington, two at Holde, and two in Henry County for outpost duty, and the Fourth Missouri State Militia to concentrate at Sedalia.

The Seventh Missouri State Militia, one company of the First Missouri State Militia, and one company of the Fourth Missouri State Militia, and Battery L, Second Missouri Artillery, are at or near this station. The troops, when concentrated at Pleasant Hill, Tabo, and Sedalia, will await orders. The commanding general did not state at what point the general concentration would be made. Will he please do so?

E. B. BROWN,

Brigadier-General.

HEADQUARTERS, Saint Louis, Mo., June 21, 1864.

(Received 6.15 p. m.)

General BROWN,
Warrensbrug, Mo.:

The necessities of the service have compelled the general commanding to order three of the seven companies of the One hundred and thirty-fifth Illinois, ordered to you yesterday, to report to General Ewing for duty in his district; the remaining four companies will take post, two at Osage Crossing and two at Gasconade. The order has been so amended. The special order telegraphed you yesterday has led you into a mistake as to the general's intention. The concentration of cavalry was intended specially to apply the cavalry which would be relieved from bridge guarding by the One hundred and thirty-fifth Illinois.

The general commanding is not yet prepared to strip the line of the river of its troops, as would be done by the order you have issued for a general concentration of all your cavalry. His idea is that they should be held well in hand, and in readiness to act at a moment's notice, fully armed and equipped; but at present, and without further developments, it is not thought advisable that your order for concentration be pu in execution. Be pleased to order accordingly. The four companies of the One hundred and thirty-fifth Illinois are ordered to be dropped at their stations without coming to Warrensburg. The order of yesterday was written during my absence from the office, by a green hand in department affairs.

O. D. GREENE,

Assistant Adjutant-General.