The following shows Clarkson's proceedings after the British nation had abolished the slave-trade.
"By the publication of his Thoughts on the Abolition of Slavery, Mr. Clarkson showed that neither he nor those connected with him, considered their work as accomplished, when the laws of his country clasped with its felons those engaged in the nefarious traffic of slaves. But the efforts of Mr. Clarkson were not confined to his pen. In 1818, he proceeded to Aix la Chapelle, at the time when the sovereigns of Europe met in congress. He was received with marked attention by the Emperor of Russia, who listened to his statements (respecting the slave-trade,) and promised to use his influence with the assembled monarchs, to secure the entire suppression of the trade in human beings, as speedily as possible. Describing his interview with this amiable monarch, in which the subject of peace societies, as well as the abolition of the slave-trade was discussed, Mr. Clarkson, in a letter to a friend, thus writes:
"'It was about nine at night, when I was shown into the emperor's apartment. I found him alone. He met me at the door, and shaking me by the hand, said, 'I had the pleasure of making your acquaintance at Paris.' He then led me some little way into the room, and leaving me there, went forward and brought me a chair with his own hand, and desired me to sit down. This being done, he went for another chair, and bringing it very near to mine, placed himself close to me, so that we sat opposite to each other.
"'I began the conversation by informing the emperor that as I supposed the congress of Aix la Chapelle might possibly be the last congress of sovereigns for settling the affairs of Europe, its connexions and dependencies, I had availed myself of the kind permission he gave me at Paris, of applying to him in behalf of the oppressed Africans, being unwilling to lose the last opportunity of rendering him serviceable to the cause.
"'The emperor replied, that he had read both my letter and my address to the sovereigns, and that what I asked him and the other sovereigns to do, was only reasonable.
"'Here I repeated the two great propositions in the address—the necessity of bringing the Portuguese time for continuing the trade (which did not expire till 1825, and then only with a condition,) down to the Spanish time, which expired in 1820; and secondly, when the two times should legally have expired, (that is, both of them in 1820,) then to make any farther continuance piracy. I entreated him not to be deceived by any other propositions; for that Mr. Wilberforce, myself, and others, who had devoted our time to this subject, were sure that no other measure would be effectual.
"'He then said very feelingly in these words, 'By the providence of God, I and my kingdom have been saved from a merciless tyranny, (alluding to the invasion of Napoleon,) and I should but ill repay the blessing, if I were not to do every thing in my power to protect the poor Africans against their oppression also.'
"'The emperor then asked if he could do any thing else for our cause. I told him he could; and that I should be greatly obliged to him if he would present one of the addresses to the Emperor of Austria, and another to the King of Prussia, with his own hand. I had brought two of them in my pocket for the purpose. He asked me why I had not presented them before. I replied that I had not the honour of knowing either of those sovereigns as I knew him; nor any of their ministers; and that I was not only fearful lest these addresses would not be presented to them, but even if they were, that coming into their hands without any recommendation, they would be laid aside and not read; on the other hand, if he (the emperor,) would condescend to present them, I was sure they would be read, and that coming from him, they would come with a weight of influence, which would secure an attention to their contents. Upon this, the emperor promised, in the most kind and affable manner, that he would perform the task I had assigned to him.
"'We then rose from our seats to inspect some articles of manufacture, which I had brought with me as a present to him, and which had been laid upon the table. We examined the articles in leather first, one by one, with which he was uncommonly gratified. He said they exhibited not only genius but taste. He inquired if they tanned their own leather, and how: I replied to his question. He said he had never seen neater work, either in Petersburg or in London. He then looked at a dagger and its scabbard or sheath. I said the sheath was intended as a further, but more beautiful specimen of the work of the poor Africans in leather; and the blade of their dagger as a specimen of their work in iron. Their works in cotton next came under our notice. There was one piece which attracted his particular notice, and which was undoubtedly very beautiful. It called from him this observation, 'Manchester,' said he, 'I think is your great place for manufactures of this sort—do you think they could make a better piece of cotton there?' I told him I had never seen a better piece of workmanship of the kind any where. Having gone over all the articles, the emperor desired me to inform him whether he was to understand that these articles were made by the Africans in their own country, that is, in their native villages, or after they had arrived in America, where they would have an opportunity of seeing European manufactures, and experienced workmen in the arts? I replied that such articles might be found in every African village, both on the coast and in the interior, and that they were samples of their own ingenuity, without any connexion with Europeans. 'Then,' said the emperor, 'you astonish me—you have given me a new idea of the state of these poor people. I was not aware that they were so advanced in society. The works you have shown me are not the works of brutes—but of men, endued with rational and intellectual powers, and capable of being brought to as high a degree of proficiency as any other men. Africa ought to have a fair chance of raising her character in the scale of the civilized world.' I replied that it was this cruel traffic alone, which had prevented Africa from rising to a level with other nations; and that it was only astonishing to me that the natives there had, under its impeding influence, arrived at the perfection which had displayed itself in the specimens of workmanship he had just seen.'"
Animated by a growing conviction of the righteousness of the cause in which he was engaged, and encouraged by the success with which past endeavours had been crowned, Mr. Clarkson continued his efficient co-operation with the friends of Abolition, advocating its claims on all suitable occasions.