Accounts of the Age of the Atlantic Revolution generally identify Britain as the nation that lost the War of American independence but thereafter escaped both revolutionary change at home and overseas. Yet, over the half century after 1788 the British Parliament first outlawed what was then the largest slave trading business in the Atlantic world and then became the first imperial power to abolish slavery throughout its transatlantic possessions. In a pioneering exercise of civil society mobilization, the British created waves of demands for the ending of its slave trade and then its transatlantic slave colonies. This phenomenon has also been recently identified as the emergence of “the modern social movement.” Decade after decade the British government became the major agent in the creation of international sanctions against the slave trade. Its example inspired and encouraged similar, if usually less successful, civil society initiatives in Europe and the Americas. At home it formed a model for the expansion of popular participation for other social reforms, by many groups previously excluded from the public arena.