Some European powers have regarded with disquieting concern the territorial expansion of the United States.  This rapid growth has resulted from the legitimate exercise of sovereign rights belonging alike to all nations, and by many liberally exercised.  Under such circumstances it could hardly have been expected that those among them which have within a comparatively recent period subdued and absorbed ancient kingdoms, planted their standards on every continent, and now possess or claim the control of the islands of every ocean as their appropriate domain would look with unfriendly sentiments upon the acquisitions of this country, in every instance honorably obtained, or would feel themselves justified in imputing our advancement to a spirit of aggression or to a passion for political predominance.  Our foreign commerce has reached a magnitude and extent nearly equal to that of the first maritime power of the earth, and exceeding that of any other.  Over this great interest, in which not only our merchants, but all classes of citizens, at least indirectly, are concerned, it is the duty of the executive and legislative branches of the Government to exercise a careful supervision and adopt proper measures for its protection.  The policy which I had in view in regard to this interest embraces its future as well as its present security.  Long experience has shown that, in general, when the principal powers of Europe are engaged in war the rights of neutral nations are endangered.  This consideration led, in the progress of the War of our Independence, to the formation of the celebrated confederacy of armed neutrality, a primary object of which was to assert the doctrine that free ships make free goods, except in the case of articles contraband of war—­a doctrine which from the very commencement of our national being has been a cherished idea of the statesmen of this country.  At one period or another every maritime power has by some solemn treaty stipulation recognized that principle, and it might have been hoped that it would come to be universally received and respected as a rule of international law.  But the refusal of one power prevented this, and in the next great war which ensued—­that of the French Revolution—­it failed to be respected among the belligerent States of Europe.  Notwithstanding this, the principle is generally admitted to be a sound and salutary one, so much so that at the commencement of the existing war in Europe Great Britain and France announced their purpose to observe it for the present; not, however, as a recognized international fight, but as a mere concession for the time being.  The cooperation, however, of these two powerful maritime nations in the interest of neutral rights appeared to me to afford an occasion inviting and justifying on the part of the United States a renewed effort to make the doctrine in question a principle of international law, by means of special conventions between the several powers of Europe and America.  Accordingly, a proposition embracing not only the rule that free ships make free goods, except contraband articles, but also the less contested one that neutral property other than contraband, though on board enemy’s ships, shall be exempt from confiscation, has been submitted by this Government to those of Europe and America.