FORT UNION, N. MEX., March 11, 1862.

Honorable W. H. SEWARD, Secretary of State, Washington City:

SIR: Since my last communication, of the 1st instant, there has been no further encounter between the forces under Colonel Canby and those of Texas, so far as heard from. On the 4th instant, Major Donaldson, then commander of the District of Santa Fe, determined to leave that city with the small force he had under his command, say 200 men, and fall back upon this place. It was then said that the advanced guard (500 strong) of the enemy had entered Albuquerque and would proceed immediately to the capital. His departure became the more necessary in order to escort and defend a large amount of Government property then on the way from Albuquerque and Santa Fe to this place. The capital having been abandoned by the United States forces, I came in company with them, and I have for the present established the executive department at Las Vegas, 30 miles west of this post.

Since my last there has been nothing official received from Colonel Canby, but we have reason to believe that he has left Fort Craig and is now on march for this place or its neighborhood. The enemy in full force are said to have entered Albuquerque four days since; if so, Colonel Canby will have an opportunity to make a detour, and march to this place, or to a position in advance of them, by the way of Manzano.

I presume he wishes to avoid a decisive engagement until he can unite with the re-enforcements that are here from Colorado Territory, of whose arrival or near approach he is doubtless apprised. Colonel Slough, from Denver City, arrived here last night, with 950 men, who from all accounts can be relied upon. These, with 300 or 400 that are already here, will give Colonel Canby a force of 2,000 regular troops; that is, American troops. He has still the fragments of three regiments of Mexican Volunteers, I think to the amount of 1,500 men, which would make his force fully 3,500. The militia have all dispersed, and have gone to preparing their for the coming harvest, and this is by far the best use that could be made of them.

Should the forces at this place unite with Colonel Canby, of which at this time I have no doubt, the enemy will be driven from the Territory. Should Colonel Canby be attacked by the enemy and suffer a defeat, with considerable loss of men and arms, we will then be in a very precarious condition until re-enforcements arrive. The whole force from this place, say 1,300 men, will leave in a few days to meet Colonel Canby should he be on this side or south of Santa Fe, and if he be still in the rear of the enemy, to engage them between two fires or operate as circumstances may require. I hope by next mail to give you the information that the enemy are either vanquished in battle or are in retreat from the Territory.

Very respectfully, your obedient servant,

HENRY CONNELLY,

Governor of New Mexico.

HEADQUARTERS EASTERN DISTRICT,
Fort Union, N. Mex., March 11, 1862.

ADJUTANT-GENERAL U. S. ARMY,

Washington, D. C.:

GENERAL: I have the honor to report that since the battle of Valverde, on the 21st of February, the state of affairs in the Department