This article examines why Boston's slave and free black population consisted of more than 1,500 people in 1750, but by 1790 Boston was home to only 766 people of African descent. This disappearing act, where the town's black population declined by at least fifty per cent between 1763 and 1790, can only be explained by exploring slavery, abolition, and their legacies in Boston. Slaves were vital to the town's economy, filling skilled positions and providing labor for numerous industries. Using the skills acquired to challenge their enslavement, Afro-Bostonians found freedom during the American revolutionary era. Nevertheless, as New England's rural economy collapsed, young white men and women from all over the region flooded Boston looking for work, driving down wages, and competing with black people for menial employment. Forced out of the labor market, many former slaves and their descendants left the region entirely. Others joined the Continental or British armies and never returned home. Moreover, many slave owners, knowing that slavery was coming to an end in Massachusetts, sold their bondsmen and women to other colonies in the Americas where slavery was still legal and profitable. Thus, the long-term legacy of abolition for black Bostonians was that Boston's original enslaved population largely disappeared, while the city became a hub of abolitionism by the 1830s. Boston's abolitionist community – many the descendants of slaveholders – did not have to live with their forefathers’ sins. Instead, they crafted a narrative of a free Boston, making it an attractive destination for runaway slaves from across the Atlantic world.