Lord Aberdeen in his correspondence with Mr. Stephenson (Oct. 13, 1841) had admitted that it would be an infringement of public law, to visit and search American vessels during times of peace, if that right were not granted by treaty. “But no such right is asserted. We sincerely desire to respect the vessels of the United States, but we may reasonably expect to know what it is we respect. Doubtless the flag is prima facie evidence of nationality of the vessel; and, if this evidence were in its nature conclusive and irrefragible, it ought to preclude all further inquiry. But it is sufficiently notorious that the flags of all nations are liable to be assumed by those who have no right or title to bear them. Mr. Stephenson himself fully admits the extent to which the American flag has been employed for the purpose of covering this infamous traffic. The undersigned joins with Mr. Stephenson in deeply lamenting the evil; and he agrees with him in thinking the United States ought not to be considered responsible for the abuse of their flag. But if all inquiry be resisted, even when carried no further than to ascertain the nationality of the vessel, and impunity be claimed for the most lawless and desperate of mankind, in the commission of the fraud the undersigned greatly fears that it may be regarded as something like an assumption of that responsibility which has been deprecated by Mr. Stephenson.... “The undersigned, although with pain, must add, that if such visit lead to the proof of the American origin of the vessel, and that she was avowedly engaged in the trade, exhibiting manacles, fetters, and other usual implements of torture, or had even a number of those unfortunates on board, no British officer could interfere further. He might give information to the cruisers of the United States, but it could not be in his power to arrest or impede the prosecution of the voyage and the success of the undertaking.” The question called for a diplomatic correspondence. In 1842, Lord Ashburton was sent as special minister to the United States, empowered to settle the Northwest Boundary, and other questions of controversy. The result of his conference with Daniel Webster, Secretary of State, was a treaty between Great Britain and the United States known as the Ashburton Treaty and as the Treaty of Washington. By the eighth article each stipulated to “maintain on the African coast an adequate squadron, to carry in all not less than eighty guns, to enforce separately and respectively the laws, rights, and obligations of the two countries for the suppression of the slave trade.”