Numbers 20. Reports of Brigadier General Thomas Ewing, Jr., U. S. Army, commanding District of the Border, of operations October 12-21.

SEDALIA, October 12, 1863-7 p. m.

COLONEL: I got here at 11 a. m. from Knobnoster, and Colonel Weer from same point, four hours behind me. I have waited all day for dispatches from General Brown, but have not a word since 11 a. m. yesterday. The failure can only be accounted for on the supposition that bushwhackers or stragglers or scouting parties cut off the messengers. A party of 4, sent by Colonel [G. H.] Hall in the night, have returned this evening, being driven back, no getting through.

I sent a strong party through this afternoon, and move all my command to-night toward Boonville. I cannot get there before noon to-morrow, as it is dark and raining violently. I can now whip Shelby with my command, and will catch up with him if he keeps his command together, unless he changes all his horses.

My convictions are that if Shelby gets out of Boonville, he will try to get out west or southwest. Hence I would go up the west side of La Mine until I could hear from General Brown, but for the fact that the road is very rough and hard to travel, and the rumors of fighting at Boonville are so frequent and persistent that I cannot fail to move toward it to-night.

I am, very respectfully, your obedient servant,

THOMAS EWING, JR.,

Brigadier-General.

Lieutenant Colonel C. W. MARSH,

Assistant Adjutant-General, &c.

FOUR MILES SOUTHWEST OF CHILHOWEE, MO.,

October 14, 1863-10.30 a. m.

GENERAL: I failed to co-operate with General Brown because I had to delay for information and make wrong moves on rumors, getting no word from him of any avail to me, and from the separation of nearly all my cavalry from the rest of my command, being unable to scout the country thoroughly for information as to the enemy's movements. Some of General Brown's messages are known to have miscarried. I started at 1 a. m. from Knobnoster, and came by Warrensburg, and reached Shelby's trail three hours behind the column. This is 10 miles southwest of Warrensburg. I can't overtake them before they reach Clinton, as my stock has had no feed or rest since 1 a. m.; but I can probably harass the, so as to keep them out of Clinton.; Colonel weer is 3 miles behind. Lazear was to leave Warrensburg at 8 this morning, going northwest, on a venture as to the enemy's whereabouts. Colonel Neill was at Warrensburg this morning, and going down to Clinton to-day. The Seventh Missouri camped last night 17 miles southeast of Lexington. I suppose a part of General Brown's command is following about half Shelby's force, which passed won Boonville and Warsaw road. I have advised commanding officers at Warrensburg, Cole Camp, and Fort Scott, and also Colonel Lazear. I will follow as long as the enemy keep together. They number 400 to 600.

THOMAS EWING, JR.,

Brigadier-General.

Major General JOHN M. SCHOFIELD, Saint Louis, Mo.