Lower California contains valuable mines of gold, silver, copper, and lead; but, for the want of capital, very few of these are worked, and this in the rudest manner possible. Nevertheless, the labor expended on them is well rewarded; and there can be no doubt that with capital and suitable means they would yield very handsome profits. The salt mines on Carmen island are capable of supplying the whole coast of Mexico and California; already the duties on this article amount to a considerable sum.

The commerce of the peninsula is now very limited, being princ.i.p.ally confined to a coasting trade with the ports of Mexico. The whole population of the country is but little more than ten thousand, and the annual imports and exports are estimated at $300,000. But in our hands this commerce, freed from the absurd restrictions imposed by Mexico, will soon receive a very great extension. La Paz will become the princ.i.p.al depot of American goods for the western coast of Mexico; and in a few years most foreign goods intended for this coast will also be deposited in the warehouses of Lower California, to be transferred to the ports of Mexico at such times and in such quant.i.ties as the demands of the market may require. In the present variable state of Mexican trade, resulting from an irregular and fluctuating tariff, which differs for each port and changes with every change of general or state administration, it is frequently necessary to transfer vessels with their cargoes from one port to another, or to keep them for weeks at sea, standing off and on, so as to enable the agents to arrange the rate of duties at the custom-house before landing the cargoes. Sometimes the consignees are obliged to send their vessels to the Sandwich islands or Valparaiso until a change of administration will enable them to avoid the exorbitant demands of some petty governor or collector of customs. Moreover, the princ.i.p.al commercial ports of this coast (Mazatlan and San Blas) are inaccessible to merchant vessels for four months of each year, and during that time are visited only by small coasters. But, with Lower California in our possession, merchant vessels of whatever character, at all seasons and in all winds, can find a refuge in La Paz, and their cargoes despatched in such quant.i.ties and to such points of the opposite coast as circ.u.mstances may justify. This place in a few years will be what Mazatlan now is, and Mazatlan experience the fate of San Blas and Acapulco.

The importance, however, of this port results mainly from its geographical position, and the influence it is likely to exert as a military and naval depot upon our commercial interests in the Pacific.

The port of San Francisco, in Upper California, should be well fortified, and every care taken to make it a harbor of refuge for our merchant and military marine, in case of a maritime war; but it must be remembered that that place is nearly fifteen hundred miles from the nearest port of Mexico, and that it is very far north of some of the best whaling grounds in the Pacific, and too distant to afford much protection to our commerce with Central America, although its position gives it a controlling influence over the commerce of Sandwich Islands, Upper California, and Oregon. In the same way a well-fortified naval station at La Paz, from its immediate proximity to the coast of Mexico, would have a most beneficial influence on our commercial and whaling interest in this part of the Pacific. The great value, in time of maritime war, of such _key_ points as La Paz, and the commanding influence exercised by them in the protection of commerce, have become settled principles in military defence; and England shows her appreciation of their truth, and the wisdom of her own policy, in establishing stations and points like St. Helena, Cape of Good Hope, Gibraltar, Malta, Corfu, and Bermuda.

Again, the growing commerce of California and Oregon, and the political importance of our possessions on the Pacific, render it necessary that we should have some means of rapid communication between them and the seat of government at Washington. This communication must be effected by the isthmus of Panama or of Tehuantepec. In either case steamers bound to Upper California and the Columbia River must have one or more intermediate depots of fuel; and in time of war it is important that these depots be established in our own rather than in a hostile territory. A glance at the map will show that La Paz is nearly equidistant from the extremities of this line; and that Tehuantepec, La Paz, and San Francisco divide into four equal parts the whole distance from Panama to Oregon. Moreover, as this ocean is peculiarly suited to steam navigation, a large part of the commerce of the Pacific must eventually be carried on in steam vessels; and in all probability not many years will elapse before a portion of our naval force in these waters is of the same character.

Under this supposition, the importance of our possessing some naval depot and harbor of refuge and repair south of Upper California is too manifest to require argument or ill.u.s.tration.

But whatever may be thought of the value of this peninsula or of the gulf as a natural boundary between us and Mexico, instead of an imaginary line drawn from the Colorado to the Pacific, thus separating a kindred people, and exposing the governments of the two territories to continual collisions, the propriety of retaining Lower California is, in my opinion, now no longer an open question. When this country was first taken possession of by the forces of the United States, the people were promised the protection of our government against Mexico, and guarantied the rights secured by our Const.i.tution; and in November, 1847, they were a.s.sured by the commander-in-chief of the Pacific squadron, (with the approbation of the Secretary of the Navy,) that this territory would be _permanently_ retained by the American government; and again, by the President of the United States, in his annual message of December, 1847, that it "should never be given up to Mexico." Acting under these a.s.surances, all the most respectable people of the territory not only refused to take part with the Mexican forces which were sent to attempt the recapture of that country from the Americans, but many of them actually took up arms in our defence, and rendered most valuable services in ridding the peninsula of the guerrilla hordes sent over from Mexico for the purpose of effecting our expulsion. In this conflict, some who thus sided with us lost their lives, many their property, and all have exposed themselves to the vengeance of the Mexican government. But these losses and dangers they have willingly encountered, in the hope of obtaining the better government of the United States. They have regarded these promises as made in good faith, and have been guided in their conduct by the a.s.surances thus held out to them by the agents of the American government; and now, for the United States to voluntarily surrender this country to the republic of Mexico, and leave these Californians exposed to the loss of life and confiscation of property for having sided with us, under the a.s.surances thus held out to them, would not only be in itself a breach of national faith, but would make us appear in the eyes of the world guilty of the most deliberate and cruel deception.

H. WAGER HALLECK, _Lieutenant of Engineers_.

Colonel R. B. MASON, _Commanding Tenth Military Department_.