Development and organization of trans-Atlantic slave trade:European manufactured goods, namely cloth and metal wares, especially firearms, went to Africa where they were exchanged for slaves. The slaves were then shipped to the Caribbean and Americas from 1532 AD, where they were sold for cash or sometimes bartered for sugar or molasses. Then the ships returned to Europe loaded with American products. In the 16th c, the Portuguese emerged as the main suppliers of slaves to Spanish colonies, having been granted special licenses