 In 1660, the population of Jamaica was about 4,500 white and 1,500 black.By the early 1670s, as the English developed sugar cane plantations worked by large numbers of slaves, black Africans formed a majority of the population.The Irish in Jamaica also formed a large part of the island's early population, making up two-thirds of the white population on the island in the late 17th century, twice that of the English population.