The most obvious and distinctive feature of the antislavery movement when compared with other examples of social activism in the age of reform is that the very nature of antislavery objectives gave the movement a dual character, domestic and imperial. Antislavery required within Britain the development of a sophisticated form of the politics of alliances that had to be reconstituted as new social forces emerged. Only by such means could sufficient leverage be developed to change state policy on the slave-trade and the reliance on slave labour in colonial economies. Abolitionists soon concluded, however, that changes in policy could only be effective if the conditions of the populations raided by the slave-traders and of the slaves in the colonies were remade in order that they would be able to live in civilized freedom. Thus antislavery also required imperial action to alter the character of societies in West Africa and in the West Indies. From the beginning of organized antislavery in the late 1780s this imperial aspect was envisaged as possessing linked institutional, moral, and commercial components.

Many abolitionists were also involved in other efforts at changing public institutions or practices. The Anglican evangelical Clapham Sect, evangelical dissenters, Quakers, rational dissenters, and Unitarians separately – and sometimes together – pursued a whole range of changes in personal behaviour, institutions, and social practices. Modern historians have, therefore, not surprisingly, regarded abolitionists as reformers. But the language of successive generations of contemporaries indicates a more complicated history as to how antislavery was perceived.