[Inclosure.]

HEADQUARTERS FOURTH CORPS, Camp at Baltimore Cross-Roads, July 1, 1863 - 5 p. m.

Major-General DIX, Commanding Department:

GENERAL: The roads were so heavy and the weather so warm this morning, that our march was slow. Colonel West will proceed 3 or 4 miles farther, and bivouac for the night. I shall remain here till to-morrow morning; I wish to have the advance fresh when it makes a demonstration. If I can do so without serious loss, shall I or shall I not destroy the bridges [railroad and Bottom's Bridge.] We have found and driven some squads of enemy's pickets, and lost 1 officer, captured. Please give bearer quick dispatch to return.

I am, respectfully, yours,
E. D. KEYES,

Major-General.

HEADQUARTERS DEPARTMENT OF VIRGINIA, White House, July 1, 1863 - 10 p. m.

Major General E. D. KEYES, Camp at Baltimore Cross-Roads:

GENERAL: The major-general commanding does not think it necessary to destroy the bridges unless there is a pressing necessity to do so.

Very respectfully, your obedient servant,

D. T. VAN BUREN,

Assistant Adjutant-General.

HEADQUARTERS FOURTH ARMY CORPS, Baltimore Cross-Roads, July 1, 1863 - 7 p. m.

Major-General DIX,
Commanding Department of Virginia:

GENERAL: We have been skirmishing for the last hour with the rebel infantry. We have list 1 man killed, and have taken a prisoner, who belongs to D. H. Hill's division. His regiment crossed Bottom's Bridge this morning. These I consider extremely significant facts, and the question is, Shall I stand fast here, or shall I fall back to-night to the White House? I send the prisoner. Please reply at once.

I have the honor to be, your obedient servant,

E. D. KEYES,

Major-General,

Commanding Fourth Corps.

[P. S.] - I have with me not above 6, 000 men.