By the tenth article of the treaty of Ghent it was expressly declared that—
Whereas the traffic in slaves is irreconcilable with the principles of humanity and justice, and whereas both His Majesty and the United States are desirous of continuing their efforts to promote its entire abolition, it is hereby agreed that both the contracting parties shall use their best endeavors to accomplish so desirable an object.
In the enforcement of the laws and treaty stipulations of Great Britain a practice had threatened to grow up on the part of its cruisers of subjecting to visitation ships sailing under the American flag, which, while it seriously involved our maritime rights, would subject to vexation a branch of our trade which was daily increasing, and which required the fostering care of Government. And although Lord Aberdeen in his correspondence with the American envoys at London expressly disclaimed all right to detain an American ship on the high seas, even if found with a cargo of slaves on board, and restricted the British pretension to a mere claim to visit and inquire, yet it could not well be discerned by the Executive of the United States how such visit and inquiry could be made without detention on the voyage and consequent interruption to the trade. It was regarded as the right of search presented only in a new form and expressed in different words, and I therefore felt it to be my duty distinctly to declare in my annual message to Congress that no such concession could be made,