HEADQUARTERS DEPARTMENT OF THE OHIO,
Grafton, Va., June 23, 1861.

COLONEL: Having completed as far as possible the necessary arrangements for transportation, &c., I left Parkersburg yesterday about 1 p. m. with the Ninth Ohio Regiment; Company I, Fourth Artillery, and the company of Chicago Rifles. I reached here about 2 a. m., having left the Ninth Regiment at Webster. The Eight and Tenth Indiana, Loomis' Michigan Battery, and Captain Barker's company of Illinois cavalry reached Clarksburg to-day. The Third and Fourth Ohio also reached Fetterman to-day. The Seventeenth and Nineteenth Ohio and Howe's battery will be up to-morrow.

From information I have received I think it more than probable that there are from fifteen hundred to three thousand rebels at Romney, intrenched with a few guns. I think their object is to cover the approaches to Winchester from and apprehended attack in this direction, as well as to cover the operations of guerrilla parties now acting towards Piedmont. It will probably be necessary to break up their establishment when I get through with other more important matters. If General Patterson could furnish the force to do it in the men time, I think it would be advantageous. their presence tends to alarm Union men even this far away. I did not find my orders intelligently carried out for the defense of Cheat river, and will go there myself to-morrow to see it properly attended to. It is very important to secure that line.

There is certainly a force of some kind near Huttonsville, with a strong advanced party intrenched near the Laurel mountain, between Philippi and Beverly. I think that the chief object of this party is to protect and furnish guerrilla parties, which are doing much damage in this region. I am of the opinion that the apprehensions of an attack in force, so constantly and so seriously reported to me that I felt it impossible to disregard them, are not well founded. It is confidently asserted that Georgia and Tennessee troops are among those at the Laurel Hill, but I do not feel certain of it. It seems to be a peculiar characteristic of the information obtained here that it is exceedingly vague and unreliable. I hope to inaugurate a better system.

My presence here was very necessary to reassure the Union men, and even if I find no force able to oppose us, I shall still be certain that it was very necessary for me to be here. As soon as I can get my command well in hand and obtain more reliable information-and I hope this will not occupy more than one or at most two days-I propose moving with all my available force from Clarksburg on Buckhannon, then on Beverly, to turn entirely the detachment at the Laurel Mountain. The troops at Philippi will advance in time to follow up the retreat of the rebels in their front. After occupying Beverly I shall move on Huttonsville, and endeavor to drive them into the mountains, whither I do not propose to follow them, unless under such circumstances as to make success certain. Having driven out the mass of their troops, and having occupied the pass by which they might return, I propose moving small columns through the country to reassure the Union men and break up any scattered parties of armed rebels. As soon as practicable, I intend to clean out the valley of the Kanawha.

Very respectfully, your obedient servant,

GEO. B. McCLELLAN,

Major-General.

Lieutenant Colonel E. D. TOWNSEND,

Assistant Adjutant-General.