Moreover, a considerable emigration[3] had already found its way into California, whose fine climate and fertile soil these people praised so much to their friends at home, that many were already on the road, and more preparing to follow them. Unknown to themselves they were to be the founders of a new commonwealth. And even at this early day Government and people were talking of a Pacific railroad, as a thing of coming necessity, and the more sanguine believers in "manifest destiny" thought as many as fifteen thousand Americans would be settled in Oregon and California during their lifetime. Thus we had important commercial views touching California, and we were throwing into it what might be considered in the light of the vanguard of an army of occupation. We had won Texas in this way, and would win Oregon too. [Illustration: BIG TREE.] It became a prime object with President Polk to secure California, peaceably if we could, forcibly if we must. Mexico was first asked to sell it, but refused. Our Government then began a secret negotiation through the American consul[4] at Monterey, which aimed to bring about the voluntary secession of California from the Mexican Republic altogether, and the setting-up instead of an independent government there under our protection. But if this plan failed—and it did not succeed—every thing was made ready to take California by force of arms. There was also fear lest England might try to obtain in California what she was about to lose in Oregon, namely, a Pacific seaport. Her ships were in those waters. Mexico owed England money, as we have said. How far this fear was well founded, is not clear; but that it was felt there can be no doubt, for we find Mr. Buchanan, our Secretary of State, instructing our consul at Monterey that "the United States would vigorously interpose to prevent California becoming a British or French colony." In furtherance of these views our squadron in the Pacific had orders to take possession of the chief ports of the country, so soon as war should begin. Fremont therefore started on his third expedition across the continent well informed of the general policy of the Government toward California. For the rest, his work was to be done wholly on Mexican ground, which, being taken with the other elements of the case, of itself seems plainly foreshadowing the views of the Government. On this journey, Fremont crossed from the head of the Arkansas into Utah, and from the Utah Desert to the Humboldt Mountains and River, both of which he named at this time for the great German scientist. From here he again struck the Sierra Nevada, which he crossed, as before, into the Sacramento Valley. [Illustration: STATES AND TERRITORIES ACQUIRED FROM MEXICO.]