During the 18th century, Middletown became the largest and most prosperous settlement in Connecticut. By the time of the American Revolution, Middletown was a thriving port, where one-third of its residents were involved in merchant and maritime activities. Some settlers held enslaved Africans as workers in the early economy of Middletown; they worked as domestic servants, laborers, and in shipping. African slaves were imported by the English in 1661 from Barbados in the Caribbean. By 1756 Middletown had the third-largest African slave population in the state of Connecticut—218 slaves to 5,446 whites.