By the laws of nations a conquered country is subject to be governed by the conqueror during his military possession and until there is either a treaty of peace or he shall voluntarily withdraw from it.  The old civil government being necessarily superseded, it is the right and duty of the conqueror to secure his conquest and to provide for the maintenance of civil order and the rights of the inhabitants.  This right has been exercised and this duty performed by our military and naval commanders by the establishment of temporary governments in some of the conquered Provinces of Mexico, assimilating them as far as practicable to the free institutions of our own country.  In the Provinces of New Mexico and of the Californias little, if any, further resistance is apprehended from the inhabitants to the temporary governments which have thus, from the necessity of the case and according to the laws of war, been established.  It may be proper to provide for the security of these important conquests by making an adequate appropriation for the purpose of erecting fortifications and defraying the expenses necessarily incident to the maintenance of our possession and authority over them.

Near the close of your last session, for reasons communicated to Congress, I deemed it important as a measure for securing a speedy peace with Mexico, that a sum of money should be appropriated and placed in the power of the Executive, similar to that which had been made upon two former occasions during the Administration of President Jefferson.

On the 26th of February, 1803, an appropriation of $2,000.000 was made and placed at the disposal of the President.  Its object is well known.  It was at that time in contemplation to acquire Louisiana from France, and it was intended to be applied as a part of the consideration which might be paid for that territory.  On the 13th of February, 1806, the same sum was in like manner appropriated, with a view to the purchase of the Floridas from Spain.  These appropriations were made to facilitate negotiations and as a means to enable the President to accomplish the important objects in view.  Though it did not become necessary for the President to use these appropriations, yet a state of things might have arisen in which it would have been highly important for him to do so, and the wisdom of making them can not be doubted.  It is believed that the measure recommended at your last session met with the approbation of decided majorities in both Houses of Congress.  Indeed, in different forms, a bill making an appropriation of $2,000,000 passed each House, and it is much to be regretted that it did not become a law.  The reasons which induced me to recommend the measure at that time still exist, and I again submit the subject for your consideration and suggest the importance of early action upon it.  Should the appropriation be made and be not needed, it will remain in the Treasury; should it be deemed proper to apply it in whole or in part, it will be accounted for as other public expenditures.