duced me to direct Franklin to halt his command near Annandale until it could be determined by reconnaissances to Vienna and toward Manassas whether these reports were true. General Cox was ordered to send his small cavalry force from Upton's Hill toward Vienna and Dranesville in one direction and toward Fairfax Court-House in the other, and Franklin to push his two squadrons as far toward Manassas as possible, in order to ascertain the true position of the enemy. With the enemy in force at Vienna and toward Lewinsville it would have been very injudicious to have pushed Franklin's small force beyond Annandale. It must be remembered that at that time we were cut off from direct communication with General Pope; that the enemy was, by the last accounts, at Manassas in strong force, and that Franklin had only from 10,000 to 11,000 men, with an entirely insufficient force of cavalry and artillery.

In order to represent this condition of affairs in its proper light to the General-in-Chief, and to obtain definite instructions from him, I telegraphed as follows:

CAMP NEAR ALEXANDRIA,

August 29, 1862-12 m.

Have ordered most of the Twelfth Pennsylvania Cavalry to report to General Barnard for scouting duty toward Rockville, Poolesville, &c.

If you apprehend a raid of cavalry on your side of river, I had better send a brigade or two of Sumner's to near Tennallytown, where, with two or three old regiments in Forts Allen and Marcy, they can watch both Chain Bridge and Tennallytown.

Would it meet your views to post the rest of Sumner's corps between Arlington and Fort Corcoran, whence they can either support Cox, Franklin, or Chain Bridge, and even Tennallytown?

Franklin has only between 10,000 and 11,000 for duty.

How far do you wish this force to advance.

GEO. B. McCLELLAN,

Major-General.

Major-General HALLECK, Washington.

CAMP NEAR ALEXANDRIA,

August 29, 1862-1 p.m.

I anxiously await reply to my last dispatch in regard to Sumner. Wish to give the order at once.

Please authorize me to attach new regiments permanently to my old brigades. I can do much good to old and new troops in that way. I shall endeavor to hold a line in advance of Forts Allen and Marcy-at least with strong advance guards. I wish to hold the line through Prospect Hill, Mackall's Minor's, and Hall's Hill. This will give us timely warning. Shall I do as seems best to me with all the troops in this vicinity, including Franklin, who I really think ought not, under present circumstances, to advance beyond Annandale?

GEO. B. McCLELLAN,

Major-General.

General HALLECK.

On the same day I received a dispatch from the General-in-Chief, in which he asks me why I halted Franklin in Annadale, to which I replied as follows:

CAMP NEAR ALEXANDRIA,

August 29, 1862-8 p.m.

By referring to my telegrams of 10.30 a.m., 12 m., and 1 p.m., together with your reply of 2.48 p.m., you will see why Franklin's corps halted at Annandale. His small cavalry force-all I had to give him-was ordered to push on as far as possible toward Manassas. It was not safe for Franklin to move beyond Annandale, under the circumstances, until we knew what was at Vienna.

General Franklin remained here until about 1 p.m., endeavoring to arrange for supplies for his command. I am responsible for both these circumstances, and do not see that either was in disobedience to your orders. Please give distinct orders in reference to Franklin's movements of to-morrow.