US Presidency
1849

In the first of these messages I informed Congress that On the 31st of March last I caused an order to be issued to our military and naval commanders to levy and collect a military contribution upon all vessels and merchandise which might enter any of the ports of Mexico in our military occupation, and to apply such contributions toward defraying the expenses of the war. By virtue of the right of conquest and the laws of war, the conqueror, consulting his own safety or convenience, may either exclude foreign commerce altogether from all such ports or permit it upon such terms and conditions as he may prescribe. Before the principal ports of Mexico were blockaded by our Navy the revenue derived from import duties under the laws of Mexico was paid into the Mexican treasury. After these ports had fallen into our military possession the blockade was raised and commerce with them permitted upon prescribed terms and conditions.