68. Action of the Powers from 1814 to 1820. At the Congress of Vienna, which assembled late in 1814, Castlereagh was indefatigable in his endeavors to secure the abolition of the trade. France and Spain, however, refused to yield farther than they had already done, and the other powers hesitated to go to the lengths he recommended. Nevertheless, he secured the institution of annual conferences on the matter, and a declaration by the Congress strongly condemning the trade and declaring that "the public voice in all civilized countries was raised to demand its suppression as soon as possible," and that, while the definitive period of termination would be left to subsequent negotiation, the sovereigns would not consider their work done until the trade was entirely suppressed.[19]
In the Treaty of Ghent, between Great Britain and the United States, ratified February 17, 1815, Article 10, proposed by Great Britain, declared that, "Whereas the traffic in slaves is irreconcilable with the principles of humanity and justice," the two countries agreed to use their best endeavors in abolishing the trade.[20] The final overthrow of Napoleon was marked by a second declaration of the powers, who, "desiring to give effect to the measures on which they deliberated at the Congress of Vienna, relative to the complete and universal
abolition of the Slave Trade, and having, each in their respective Dominions, prohibited without restriction their Colonies and Subjects from taking any part whatever in this Traffic, engage to renew conjointly their efforts, with the view of securing final success to those principles which they proclaimed in the Declaration of the 4th February, 1815, and of concerting, without loss of time, through their Ministers at the Courts of London and of Paris, the most effectual measures for the entire and definitive abolition of a Commerce so odious, and so strongly condemned by the laws of religion and of nature."[21]
Treaties further restricting the trade continued to be made by Great Britain: Spain abolished the trade north of the equator in 1817,[22] and promised entire abolition in 1820; Spain, Portugal, and Holland also granted a mutual limited Right of Search to England, and joined in establishing mixed courts.[23] The effort, however, to secure a general declaration of the powers urging, if not compelling, the abolition of the trade in 1820, as well as the attempt to secure a qualified international Right of Visit, failed, although both propositions were strongly urged by England at the Conference of 1818.[24]
69. The Struggle for an International Right of Search, 1820–1840. Whatever England's motives were, it is certain that only a limited international Right of Visit on the high seas could suppress or greatly limit the slave-trade. Her diplomacy was therefore henceforth directed to this end. On the other hand, the maritime supremacy of England, so successfully
asserted during the Napoleonic wars, would, in case a Right of Search were granted, virtually make England the policeman of the seas; and if nations like the United States had already, under present conditions, had just cause to complain of violations by England of their rights on the seas, might not any extension of rights by international agreement be dangerous? It was such considerations that for many years brought the powers to a dead-lock in their efforts to suppress the slave-trade.
At first it looked as if England might attempt, by judicial decisions in her own courts, to seize even foreign slavers.[25] After the war, however, her courts disavowed such action,[26] and the right was sought for by treaty stipulation. Castlereagh took early opportunity to approach the United States on the matter, suggesting to Minister Rush, June 20, 1818, a mutual but strictly limited Right of Search.[27] Rush was ordered to give him assurances of the solicitude of the United States to suppress the traffic, but to state that the concessions asked for appeared of a character not adaptable to our institutions. Negotiations were then transferred to Washington; and the new British minister, Mr. Stratford Canning, approached Adams with full instructions in December, 1820.[28]
Meantime, it had become clear to many in the United States that the individual efforts of States could never suppress or even limit the trade without systematic co-operation. In 1817 a committee of the House had urged the opening of negotiations looking toward such international co-operation,[29] and a Senate motion to the same effect had caused long debate.[30] In 1820 and 1821 two House committee reports, one of which recommended the granting of a Right of Search, were adopted by the House, but failed in the Senate.[31] Adams, notwithstanding this, saw constitutional objections to the
plan proposed by Canning, and wrote to him, December 30: "A Compact, giving the power to the Naval Officers of one Nation to search the Merchant Vessels of another for Offenders and offences against the Laws of the latter, backed by a further power to seize and carry into a Foreign Port, and there subject to the decision of a Tribunal composed of at least one half Foreigners, irresponsible to the Supreme Corrective tribunal of this Union, and not amendable to the controul of impeachment for official misdemeanors, was an investment of power, over the persons, property and reputation of the Citizens of this Country, not only unwarranted by any delegation of Sovereign Power to the National Government, but so adverse to the elementary principles and indispensable securities of individual rights, ... that not even the most unqualified approbation of the ends ... could justify the transgression." He then suggested co-operation of the fleets on the coast of Africa, a proposal which was promptly accepted.[32]
The slave-trade was again a subject of international consideration at the Congress of Verona in 1822. Austria, France, Great Britain, Russia, and Prussia were represented. The English delegates declared that, although only Portugal and Brazil allowed the trade, yet the traffic was at that moment carried on to a greater extent than ever before. They said that in seven months of the year 1821 no less than 21,000 slaves were abducted, and three hundred and fifty-two vessels entered African ports north of the equator. "It is obvious," said they, "that this crime is committed in contravention of the Laws of every Country of Europe, and of America, excepting only of one, and that it requires something more than the ordinary operation of Law to prevent it." England therefore recommended:—