Aside from the purely economic questions, there was also the clamorous ethical debate. Great Britain took pride in being a leader in suppressing slavery, ending it in its empire in 1833, and the end of the Atlantic slave trade was enforced by British vessels. Confederate diplomats found little support for American slavery, cotton trade or no. A series of slave narratives about American slavery was being published in London. It was in London that the first World Anti-Slavery Convention had been held in 1840; it was followed by regular smaller conferences. A string of eloquent and sometimes well-educated Negro abolitionist speakers criss-crossed not just England but Scotland and Ireland as well. In addition to exposing the reality of America's shameful and sinful chattel slavery—some were fugitive slaves—they put the lie to the Confederate position that negroes were "unintellectual, timid, and dependant", and "not equal to the white man...the superior race," as it was put by Confederate Vice-President Alexander H. Stephens in his famous Cornerstone Speech. Frederick Douglass, Henry Highland Garnet, Sarah Parker Remond, her brother Charles Lenox Remond, James W. C. Pennington, Martin Delany, Samuel Ringgold Ward, and William G. Allen all spent years in Britain, where fugitive slaves were safe and, as Allen said, there was an "absence of prejudice against color. Here the colored man feels himself among friends, and not among enemies". One speaker alone, William Wells Brown, gave more than 1,000 lectures on the shame of American chattel slavery.