First, working amiably with his foreign policy rival, Secretary of State William Seward, Sumner helped ratify a treaty with Great Britain to collaborate in stopping the transatlantic slave trade. Although the trade had been banned in the United States for decades, smugglers continued to kidnap men and women in Africa to bring to American shores forcibly. The new treaty permitted both parties to investigate any ships coming from either country that appeared to be transporting enslaved human beings.
