It is my duty to state to Your Excellency that the prospect now before the country is alarming. My latest advices from Louisiana state that the main body of the enemy has already crossed old Red River at Kanett's Ferry, 20 miles below Natchitoches, while his cavalry, 8,000 strong, was devastating the country in all directions. His entire force now moving up the Red River Valley is estimated at 30,000 men. Four gun-boats were at Grand Ecore. I fear that this force will over whelm our meager forces, and that the enemy will advance to Shreveport and probably devastate the heavy slave-holding district of Easten Texas. Official information received yesterday states that Steele with 10,000 veterans is on the march from Little Rock to form a junction with Sherman and Banks. His army has already passed through Arkadelphia.

The object doubtless is to penetrate the wheat region of Texas and destroy our manufacturing establishments and iron-works at Marshall and Jefferson. As Your Excellency is aware, I am making the endeavor to protect our cotton trade with Mexico and to put the enemy on the defensive on the Rio Grande and on the western coast, but these are secondary considerations compared with he safety of the great agricultural regions of the State. If I am enabled to thrown into the field the large body of men which the adoption of the plan proposed will produce I hope to be able to keep up the trade with Mexico and sustain military operations in the extreme west. If I am left without troops necessity will compel the withdrawal of these forces and the placing in the ranks at once of the large body of conscript teamsters.

The late advance of the enemy to Laredo, where he was gallantly repulsed by Colonel Benavides, shows that he has his eyes upon the upper Rio Grande and the importance of our cotton trade. Without an adequate force to protect it the trade cannot be sustained. With the reserve corps in the field, I hope to be able not only to do this and drive the enemy to the coast, but to interpose such a force on our norther and eastern border as will check his progress. Appealing to Your Excellency for co-operation and aid, I would respectfully ask that if those views are acceptable you will immediately issue orders declaring that the State troops in the field will form the nucleus of the reserve corps, with such orders respecting the men between eighteen and forty-five as Your Excellency may approve. In the mean time the State troops in the field will remain as at present, awaiting these orders. They are still being sustained by the Confederate authorities, previous orders not having been countermanded.

It has been my disposition to act with the greatest fairness toward Your Excellency, and I have therefore left the troops entirely at your control, and have given no indication of an issue between Your Excellency and myself concerning them.

Your Excellency has the facts before you and can see that the State is in the greatest danger, and that the organization of the State troops is not equal to the emergency. Such is my deliberate opinion, and it is sustained by the expression of the press of the State, whose opportunities for gaining correct information entitle its opinions to consideration.

Soliciting an early reply, I remain, very respectfully, your obedient servant,

J. B. MAGRUDER,

Major-General, Commanding District of Texas, &c.