The British Empire was a legacy of three centuries of maritime and colonial activities around two great trading networks focused on the West Indies and the East Indies. The Atlantic trades found in the Caribbean islands of St Kitts, Barbados and Jamaica provided the first great source of colonial wealth, followed by the larger North American mainland colonies. This success was partly based on slave labor from West Africa. Until abolition of the trade in 1807, British companies supplied the colonies with slaves, along with capital and manufactured goods, including cloth and hardware of various kinds. Britain imported agricultural commodities, including sugar, tobacco and rice. By the late 18th century North America and the West Indies took 57% of British exports and supplied 32% of imports. This was not free trade even the carriage of goods was controlled. The British Navigation Acts required that British ships staffed by British sailors were used, and that they trade between British ports and those within the empire.