It is the right of the conqueror to levy contribution upon the enemy in their seaports, towns, or provinces which may be in his military possession by conquest and to apply the same to defray the expenses of the war.  The conqueror possesses the right also to establish a temporary military government over such seaports, towns, or provinces and to prescribe the conditions and restrictions upon which commerce with such places may be permitted.  He may, in his discretion, exclude all trade, or admit it with limitation or restriction, or impose terms the observance of which will be the condition of carrying it on.  One of these conditions may be the payment of a prescribed rate of duties on tonnage and imports.

In the exercise of these unquestioned rights of war, I have, on full consideration, determined to order that all the ports or places in Mexico which now are or hereafter may be in the actual possession of our land and naval forces by conquest shall be opened while our military occupation may continue to the commerce of all neutral nations, as well as our own, in articles not contraband of war, upon the payment of prescribed rates of duties, which will be made known and enforced by our military and naval commanders.

While the adoption of this policy will be to impose a burden on the enemy, and at the same time to deprive them of the revenue to be derived from trade at such ports or places, as well as to secure it to ourselves, whereby the expenses of the war maybe diminished, a just regard to the general interests of commerce and the obvious advantages of uniformity in the exercise of these belligerent rights require that well-considered regulations and restrictions should be prepared for the guidance of those who may be charged with carrying it into effect.

You are therefore instructed to examine the existing Mexican tariff of duties and report to me a schedule of articles of trade to be admitted at such ports or places as may be at any time in our military possession, with such rates of duty on them and also on tonnage as will be likely to produce the greatest amount of revenue.  You will also communicate the considerations which may recommend the scale of duties which you may propose, and will submit such regulations as you may deem advisable in order to enforce their collection.

As the levy of the contribution proposed is a military right, derived from the laws of nations, the collection and disbursement of the duties will be made, under the orders of the Secretary of War and the Secretary of the Navy, by the military and naval commanders at the ports or places in Mexico which may be in possession of our arms.  The report requested is therefore necessary in order to enable me to give the proper directions to the War and Navy Departments.

JAMES K POLK.

TREASURY DEPARTMENT, March 30, 1847.

The PRESIDENT.

SIR:  Your instructions of the 23d instant have been received by this Department, and in conformity thereto I present you herewith, for your consideration, a scale of duties proposed to be collected as a military contribution during the war in the ports of Mexico in possession of our Army or Navy by conquest, with regulations for the ascertainment and collection of such duties, together with the reasons which appear to me to recommend their adoption.