Warrensburg with considerable force, and moving in the direction of Lexington, is now beyond doubt. Many persons are coming in hourly from that vicinity, confirming the fact.

His force is variously estimated at from 5,000 to 15,000. His cavalry took possession of Georgetown on Tuesday. The commander at Booneville sent me two dispatches last night, asking for re-enforcements, as that place was also threatened by 600 men. I had, however, anticipated this, and sent a detachment up the river yesterday, sufficient to drive them off, if they do their duty.

Lieutenant Pease, a very intelligent officer, arrived last night with dispatches from Colonel Mulligan, at Lexington, and reports all quiet there. They had not heard of Price's advance, but the colonel informed me that he had secured the money in the bank at that place, and was taking steps to secure that of other banks, in obedience to my orders. I also ordered him, immediately after his arrival, to commence fortifying Lexington, which he informs me he is doing. No troops from Kansas, except about 300, had arrived. Nothing was known there of General Pope's movements. Affairs south of this, and in Calloway County, are being vigorously straightened out by some detachments I sent out some days ago.

The mail closes.

I am, very respectfully, your obedient servant,

JEFF. C. DAVIS,

Colonel, Commanding.

Major General JOHN C. FREMONT, Saint Louis, Mo.

HEADQUARTERS WESTERN DEPARTMENT,
Saint Louis, September 12, 1861.

What is your effective force, and how located?

J. C. FREMONT,

Major-General, Commanding.

Colonel JEFFERSON C. DAVIS, Jefferson City.

JEFFERSON CITY, September 12, 1861.

Two Indiana regiments, 1,986; Twenty-fifth Illinois, 860; Fifth Iowa, 850; Davidson's battery, 4 pieces, 4 horses each, and 99 men; Home Guards, 1,362, not efficient-want of organization and equipments. Some ammunition wanted for all. Will present requisition.

JEFF. C. DAVIS.

Major General JOHN C. FREMONT.

HEADQUARTERS WESTERN DEPARTMENT,
Saint Louis, September 12, 1861.

Colonel JEFFERSON C. DAVIS, Jefferson City:

The following information received here from General Pope, at Hudson, to-day: "Illinois Sixteenth and Kansas Second, 1,100 strong, with two pieces of artillery, go this morning to Saint Joseph. Green and Bevier are aiming to cross the Missouri at Glasgow in three columns,