With Sonora, a State on our southern border, and in close proximity to one of our finest harbors on this coast, in possession of a powerful foreign Government, which has given the most unmistakable evidence of its sympathy with the rebellion, what might we expect but a bold attempt to seize the glittering prize of California, the bright occidental star of our Union. In the fall of 1861 I urged upon the Department to permit me to send a force of U. s. troops and occupy the city of Guaymas, and I deeply regret that the authority was no tgranted. It could have been done with the acquiescenece of the State authorities and entirely without disturbing our friendly relations with Mexico, and we should have gained such a foothold in that country by this time as would have revented any foregin Government from interfering with us. At the time I urged the occupation of Guaymas I deemed it a measure of vital imortance as a precautionary measure to prevent the rebel forces from occupying the State of Sonor and threatening our southern frontier. The fact is, the northern and western States of Mexico must maintain their independence as a Republic or attach themselves to the United States. Should those States be subjugated to any foregin Government out possessions on this coast would be imperiled. I have referred only to the States of Mexico on the immediate frontier of my department; but should it be the policy of our Government to enforce the doctrines so dear to every American heart, I can guarantee that the loyal men on the pacific Coast will not be behind their bretheen of the Atlantic, aznd will meet them half way in the halls of the Montezumas, which may once more be occupied by an American army.

With great respect, your most obedient servant,

G. WRIGHT,

Brigadier-General, U. S. Army, Commanding.

U. S. STEAMER SARANAC, Mare Island, March 15, 1864.

Brigadier General G. WRIGHT,

Commanding Department of the Pacific, San Francisco, Cal.:

SIR: I have the honor to acknowledge the receipt of your letter of the 10th [11th] instant, inclosing one from the special duty collector to Asst. Adjt. General R. C. Drum, in reference to the position of the revenue cutter Shubrick, co-operating with the fortification at Fort Point, &c. In reply to the suggestion of placing a man-of-war outside of the Golden Gate, I would state that although I concur with you as to the advantage of such an arrangement, it is not in my power to carry it into operation. The Saranac, under my immediate command, is but half manned and cannot be available until a crew is procured, and even then, unless I should receive other instructioins from the admiral than those I have, I will not be able toremain at SanFrancisco. The only other man-of-war at my disposal is the Narragansett, which vessel is now undergoing repairs at Mare Island Navy-Yard, and is also almost entirely without a crew, and until one can be shipped for her will be of course unavaialbe; but every effort is making to procure crews for both vessels in order to be ready for any emergency. It would give me much pleasure at all times to co-operate with you in the proteciton of the harbor of San Francisco in such manneras would most efficiently secure that object. I fear it will be very difficult to get men to serve on board of any vessel of war permanently stationed in the harbor of San Francisco unless the Government will authorize