It is manifest to all who have observed the actual condition of the Mexican Government for some years past and at present that if these Provinces should be retained by her she could not long continue to hold and govern them.  Mexico is too feeble a power to govern these Provinces, lying as they do at a distance of more than 1,000 miles from her capital, and if attempted to be retained by her they would constitute but for a short time even nominally a part of her dominions.  This would be especially the case with Upper California.

The sagacity of powerful European nations has long since directed their attention to the commercial importance of that Province, and there can be little doubt that the moment the United States shall relinquish their present occupation of it and their claim to it as indemnity an effort would be made by some foreign power to possess it, either by conquest or by purchase.  If no foreign government should acquire it in either of these modes, an independent revolutionary government would probably be established by the inhabitants and such foreigners as may remain in or remove to the country as soon as it shall be known that the United States have abandoned it.  Such a government would be too feeble long to maintain its separate independent existence, and would finally become annexed to or be a dependent colony of some more powerful state.

Should any foreign government attempt to possess it as a colony, or otherwise to incorporate it with itself, the principle avowed by President Monroe in 1824, and reaffirmed in my first annual message, that no foreign power shall with our consent be permitted to plant or establish any new colony or dominion on any part of the North American continent must be maintained.  In maintaining this principle and in resisting its invasion by any foreign power we might be involved in other wars more expensive and more difficult than that in which we are now engaged.

The Provinces of New Mexico and the Californias are contiguous to the territories of the United States, and if brought under the government of our laws their resources—­mineral, agricultural, manufacturing, and commercial—­would soon be developed.

Upper California is bounded on the north by our Oregon possessions, and if held by the United States would soon be settled by a hardy, enterprising, and intelligent portion of our population.  The Bay of San Francisco and other harbors along the Californian coast would afford shelter for our Navy, for our numerous whale ships, and other merchant vessels employed in the Pacific Ocean, and would in a short period become the marts of an extensive and profitable commerce with China and other countries of the East.

These advantages, in which the whole commercial world would participate, would at once be secured to the United States by the cession of this territory; while it is certain that as long as it remains a part of the Mexican dominions they can be enjoyed neither by Mexico herself nor by any other nation.