FAIRFAX, VA.

Colonel HAUPT:

I have just seen an intelligent contraband that left Manassas this morning about daylight. Says there was no infantry at Manassas; all cavalry. Nothing burned, but contended themselves with cooking and eating.

BRAYTON.

H. HAUPT.

ALEXANDRIA DEPOT, VA., August 27, 1862-10.50 a.m.

Major General H. W. HALLECK,

General-in-Chief:

I venture the suggestion: As soon as the cars return which carried troops to Union Mills I propose to load the whole with subsistence, but on top and inside 1,500 or 2,000 more men, and endeavor by all means to work the train through. The most serious matter, if true, is the capture of some pieces of our artillery, which, if turned against our trains, would render an advance impossible. I am told that a battery left here yesterday and should this morning be near Manassas, but I fear it has no infantry support. I am not advised of any movement, except those made under my direction, by rail. Do you approve of my sending forward the subsistence train in manner proposed? If so, please answer. I would suggest that artillery, with a good infantry support, should be sent forward immediately. I propose this plan: Load a battery or part of a battery on cars, carry with it a sufficient infantry support; let this precede the supply train to some point where the battery can be unloaded and advanced by common road to Manassas, to recapture, if possible, the pieces taken, and prevent them from being used against the train. I have a strong force. One wrecking and one construction train now on the ground, with very efficient men. The track will be cleared and reconstructed in the shortest possible time, so as to advance trains.

H. HAUPT.

FAIRFAX, VA., August 27, 1862.

Honorable E. M. STANTON,

Secretary of War:

The enemy, both cavalry and infantry, made an attack upon Manassas last evening about 9 o'clock, and there were no troops to defend the place, the Twelfth Pennsylvania Cavalry having been on guard at White Plains Station to about 3 o'clock p.m., a part of one company only remaining and one battery of artillery, the Eleventh New York. They first made a dash at the railroad trains with a small portion of their force near Bristoe, which drew all the cavalry which was left at Manassas to that point. Not twenty minutes after that the raid was made at Manassas. Colonel Pierce was very sick upon his bed at the hospital. He did what he could, but four guns of the battery were immediately taken by the enemy. He remained until they retreated to the woods, when he was brought to this place in an ambulance. McDowell's, Banks', and some other brigade wagon trains are this side of Centreville, and should be protected, as they will undoubtedly be attacked. A large number of Government cattle are at Manassas without protection.

B. H. MORSE,

Government Agent.