It was the brains and statesmanship of Wm. L. Marcy, when he was secretary of war under President Polk, that inaugurated and generaled the movements that resulted in our securing possession of California–by his expeditions, sent by sea and by land, of regular forces, followed by the volunteer regiment of one thousand men, under the command of Col. Jonathan Stevenson, as the following able State paper indicates:

[Confidential.]

WAR DEPARTMENT, WASHINGTON, June 3, 1846.

SIR.– I herewith send you a copy of my letter to the governor of Missouri for an additional force of one thousand mounted men. The object of thus adding to the force under your command is not, as you will perceive, fully set forth in that letter, for the reason that it is deemed prudent that it should not, at this time, become a matter of public notoriety; but to you it is proper and necessary that it should be stated.

It has been decided by the president to be of the greatest importance in the pending war with Mexico to take the earliest possession of Upper California. An expedition with that view is hereby ordered, and you are designated to command it. To enable you to be in sufficient force to conduct it successfully this additional force of a thousand mounted men has been provided, to follow you in the direction of Santa Fe, to be under your orders or the officer you may leave in command at Santa Fe.

W. L. Marcy

W. L. Marcy

It cannot be determined how far this additional force will be behind that designated for the Santa Fe expedition, but it will not probably be more than a few weeks. When you arrive at Santa Fe with the force already called, and shall have taken possession of it, you may find yourself in a condition to garrison it with a small part of your command (as the additional force will soon be at that place), and with the remainder, press forward to California. In that case you will make such arrangements as to being followed by the reinforcements before mentioned, as in your judgment may be deemed safe and prudent. I need not say to you that in case you conquer Santa Fe (and with it will be included the department of the State of New Mexico), it will be important to provide for retaining safe possession of it. Should you deem it prudent to have still more troops for the accomplishment of the object herein designated, you will lose no time in communicating that opinion on that point, and all others connected with the enterprise, to this department. Indeed you are hereby authorized to make a direct requisition for it upon the governor of Missouri.

It is known that a large body of Mormon emigrants are en route to California for the purpose of settling in that country. You are desired to use all proper means to have a good understanding with them, to the end that the United States may have their co-operation in taking possession of and holding that country. It has been suggested here that many of these Mormons would willingly enter into the service of the United States and aid us in our expedition against California. You are hereby authorized to muster into service such as can be induced to volunteer; not, however, to a number exceeding one-third of your entire force. Should they enter the service they will be paid as other volunteers, and you can allow them to designate, so far as it can be properly done, the persons to act as officers thereof. It is understood that a considerable number of American citizens are now settled on the Sacramento river, near Sutter’s establishment, called “Nueva Helvetia,” who are well disposed toward the United States. Should you, on your arrival in the country, find this to be the true state of things there, you are authorized to organize and receive into the service of the United States such portion of these citizens as you may think useful to aid you to hold the possession of the country. You will in that case allow them, so far as you shall judge proper, to select their own officers. A large discretionary power is invested in you in regard to these matters, as well as to all others, in relation to the expedition confided to your command.

The choice of routes by which you will enter California will be left to your better knowledge and ampler means of getting accurate information. We are assured that a southern route (called the Caravan route, by which the wild horses are brought from that country into New Mexico) is practicable, and it is suggested as not improbable that it can be passed over in the winter months, or at least late in autumn. It is hoped that this information may prove to be correct.

In regard to routes; the practicability of procuring needful supplies for men and animals, and transporting baggage is a point to be well considered. Should the president be disappointed in his cherished hope that you will be able to reach the interior of Upper California before winter, you are then desired to make the best arrangement you can for sustaining your forces during the winter, and for an early movement in the spring. Though it is very desirable that the expedition should reach California this season (and the president does not doubt you will make every possible effort to accomplish this object), yet if, in your judgment, it cannot be undertaken with a reasonable assurance of success, you will defer it, as above suggested, until spring. You are left unembarrassed by any specific directions in the matter.

It is expected that the naval forces of the United States which are now, or will soon be in the Pacific, will be in possession of all the towns on the seacoast, and will co-operate with you in the conquest of California. Arms, ordnance, munitions of war, and provisions to be used in that country, will be sent by sea to our squadron in the Pacific for the use of the land forces.

Should you conquer and take possession of New Mexico and Upper California, or considerable places in either, you will establish temporary civil government therein, abolishing all arbitrary restrictions that may exist, so far as it may be done with safety.

In performing this duty, it would be wise and prudent to continue in their employment all such of the existing officers as are known to be friendly to the United States, and will take the oath of allegiance to them. The duties of the custom-house ought, at once, to be reduced to such a rate as may be barely sufficient to maintain the necessary officers without yielding any revenue to the government. You may assure the people of these provinces that it is the wish and design of the United States to provide for them a free government with the least possible delay, similar to that which exists in our territories. They will then be called on to exercise the rights of freemen in electing their own representatives to the territorial legislature. It is foreseen that what relates to the civil government will be a difficult and unpleasant part of your duty, and much must necessarily be left to your own discretion. In your whole conduct you will act in such a manner as best to conciliate the inhabitants and render them friendly to the United States.

It is desirable that the usual trade between the citizens of the United States and the Mexican provinces should be continued, as far as practicable, under the changed condition of things between the two countries. In consequence of extending your expedition into California it may be proper that you should increase your supply for goods to be distributed as presents to the Indians. The United States superintendent of Indian affairs at St. Louis will aid you in procuring these goods. You will be furnished with a proclamation in the Spanish language, to be issued by you and circulated among the Mexican people on your entering into or approaching their country. You will use your utmost endeavors to have the pledges and promises therein contained carried out to the utmost extent.

I am directed by the president to say that the rank of brevet brigadier-general will be conferred on you as soon as you commence your movement toward California, and sent round to you by sea or over the country, or to the care of the commandant of our squadron in the Pacific. In that way cannon, arms, ammunition and supplies for the land forces will be sent to you.

Very respectfully, your obedient servant,

W.L. MARCY,

Secretary of War.

COLONEL S. N. KEARNEY, Fort Leavenworth, Missouri.