English colonist William Vassall (1592–1656) is remembered both for promoting religious freedom in New England and commencing his family's ownership of slave plantations in the Caribbean. A patentee of the Massachusetts Bay Company, Vassall was among the merchants who petitioned Puritan courts for greater civil liberties and religious tolerance. In 1647, he and John Child published New-England’s Jonas cast up in London, a tract describing the efforts of colonial petitioners. By early 1648, Vassall moved to Barbados to establish a slave-labor sugar plantation. He and his descendants were among the Caribbean's leading planters, enslaving more than 3,865 people before Britain abolished slavery in 1833.