This article focuses on the historiography of abolition and antislavery. Abolitionism is an idea, articulated through language that emerged in the eighteenth century and propelled people to act. It ultimately changed the world. People came to believe that God had endowed all humans with the inalienable right to be free and that slavery was an intolerable evil that must be abolished. Most scholars agree with this basic definition of abolitionism. But they have long disagreed about its significance and the process by which the idea led to action and political change. The discussion covers the age of gradual abolitionism (1770s–1820s), gradual abolition in the British Caribbean and French Caribbean, the age of immediate abolitionism (1820s–1860s), the French abolition movement, and the road to civil war and emancipation in the United States.