Very soon thereafter the Emperor of Russia offered to use his good offices as mediator and after a short discussion, his proposal was accepted. To this end there was concluded on June 30, 1822, a convention in which the adjustment of the claims for indemnity was left to a mixed commission. This action was followed by desultory and extended discussions which terminated, nevertheless, in the final disposition of the controversy. The point of difference was decided in favor of the United States. In handing down his decision the Emperor held that the limitations as to the restitution of public property bore no relation to private property. In effect, he said that the treaty prohibited the carrying away of any private property whatever from the places and territories stipulated in Article I of the Treaty of Ghent. He contended that "the United States was entitled to consider as having been carried away all slaves who had been transported from those territories on board of English vessels within the waters of American territories and who for that reason had not been restored."[71]
In compliance with the decision of the Emperor of Russia a mixed commission, one commissioner and one arbitrator from Great Britain as well as the United States met July 30, 1822, at Washington, D.C., under the Emperor's mediation.[72] For the United States Langdon Cheves was the commissioner and Henry Sewell the arbitrator; for Great Britain George Jackson was the commissioner and John McTavish the arbitrator. George Hay was appointed, also, by the President of the United States to give such information and support that might be needed since individual claimants could not be present. The purpose of the commission was to prove the average value of the Negroes at the time of the ratification of the treaty and to determine the validity of individual claims. In the event no agreement could be reached recourse was had to the Emperor of Russia whose decision would be "final and conclusive." This action was insisted upon by America, whereas Great Britain persisted in refusing to submit such matters to the Emperor. Their progress, as a result, was not very marked. In considering the "definitive lists"[73] of claims these commissioners encountered many more doubtful and intricate problems. Claims not contained in this list were not to be taken cognizance of; nor was the British government required to make compensation for them. With respect to compensation, Great Britain promised to produce all evidence which was in the possession of her naval and military officers concerning the number of slaves carried away. It was provided by the commission that no payment was to be made within twelve months. September 11, 1822, the board unanimously agreed on the average value of slaves as follows:
| Each slave from Louisiana | $580 |
| Each slave from Georgia, South Carolina, Alabama | 390 |
| Each slave from Maryland, Virginia and other States | 280 |
The next difficulty of the board occurred in regard to the allowance of interest on claims. Concerning this point, Cheves held that a reasonable compensation for the injury sustained should have been granted. "A just compensation," said Cheves, "is the reestablishment of the thing taken away with an equivalent for the use of it during the period of detention." In reply to this Jackson held that the convention of 1822 did not grant the commissioners the power to fix interests and, besides, that interests not being a part of the debt could not be allowed. Realizing the futility of his claims Cheves offered to submit the difference to arbitration, but Jackson declined.
Equally difficult questions arose in regard to the slaves taken away from Dauphin Island in Mobile Bay.[74] This island, controlled by the British during the war, was later surrendered to the United States. Concerning this Jackson held that it was not legally at the time of the ratifications of the treaty a part of the United States, that is, it was not a part of Louisiana but belonged to West Florida, which was not ceded to the United States until 1819.[75] In regard to this Cheves offered to refer these claims to arbitration, but in this view Jackson refused to acquiesce. The situation did not become any better even when Rufus King was sent as our minister to England to succeed Henry Clay who became John Quincy Adams's Secretary of State.
Continued disagreement of the representatives of Great Britain and the United States resulted. Their failure to agree upon the provisions of the Convention of 1822—that matters under dispute be referred to arbitration made the work of this convention of little avail. Clay's offer of settlement was not favorably received in Great Britain. As to a basis of compromise, Clay said that the "total number of slaves on the definitive list was 3,601; that the entire value of all the property for which the indemnity was claimed including interest might be stated at $2,693,120." Realizing that this large sum would never be secured, Clay suggested that $1,151,800 might be used as the minimum in the negotiation. He used as a guide the fact that Parliament had appropriated 250,000 pounds to cover the awards of the commission. This sum, Mr. King observed also, was nearly the sum mentioned as a minimum by Clay in his instructions to him. Even with this information, the commissioners made little progress.
On the other hand, Mr. Vaughan, the British Envoy at Washington, said April 12, 1826, "that His Majesty's Government regretted to find themselves under the absolute impossibility of accepting the terms of compromise offered by the envoy from the United States in London." He did not admit, moreover, that the question of interest should be referred to arbitration, but maintained that the demand was unwarranted by the convention and unfounded by the Law Officers of the Crown.[76] In reply to his observation, Clay informed Vaughan of the fact that Great Britain's representatives had refused to refer many questions to arbitration and that if this refusal to cooperate in this regard should be upheld it would virtually be making him the final judge of every question of difference that arose in the joint commission.[77] This disagreement continued until 1825, when the commissioners met to collect and weigh evidence.
Soon thereafter, Albert Gallatin, who had been appointed Envoy of the United States to London, was authorized to treat with Canning on the oft-discussed question. During the first interview he discovered that, while there was a great reluctance to recede from the ground already taken by Jackson, there was also a disposition to settle that controversy.[78] Following the instructions given to King, Gallatin used the 250,000 pounds as the basis of settlement. This sum he was authorized to accept. He, however, did not make this offer known immediately but waited for the formal offer of $1,200,000 from the British Government; and in conformity with his instruction of a later date, Gallatin offered as an ultimatum an acceptance of $1,204,960, which the British Government reluctantly agreed to pay.[79]
On November 13, 1826, a convention to carry out this agreement was concluded. The amount specified above was to cover all claims under the award of the Emperor of Russia. It provided, moreover, that the money was to be paid in Washington, in the current money of the United States, in two installments; the first twenty days after the British Minister in the United States should have been officially notified of the ratifications of the convention, and the second August 1, 1827. In this way the convention of 1822 was annulled, save as to the two articles relating to the average value of slaves which had been carried into effect, and as to the third article as related to the definitive list which had also been carried out.[80] This ended the work of the board. After ratification had been exchanged the board adjourned, March 26, 1827.