The Civil War historian James M. McPherson states that "there were almost as many kinds of abolitionists as there were individuals in the movement." McPherson identifies three distinct factions within the abolitionist movement: the non-church-oriented Garrisonians; the evangelicals, who worked through their churches, offering a religious critique of slavery; and the political abolitionists, who strived to achieve their goal by working within the existing political structure. Add to these factions the radical abolitionists, whose goal was to eradicate slavery by means of violent revolution. Black abolitionists could be found within each faction.

Olaudah Equiano directed his attack against the international slave trade to the queen of England, imploring her to support antislavery bills being discussed in Parliament: I presume . . . gracious Queen, to implore your interposition with your royal consort, in favor of the wretched Africans; that, by your Majesty's benevolent...