Although slavery had been an established institution in Africa for more than a millennium and the trans-Saharan, Red Sea, and East African slave trade had been pervasive for many centuries, the Atlantic slave trade differed from them by its numbers, intensity, and the changes it produced within the societies of the African continent. More than 11 million Africans were exported to the Americas from the coast of western Africa. It was mostly conducted in just three hundred years and concentrated in specific regions during different centuries, creating an uneven disruption of African societies along the coast. More than half the trade took place in the eighteenth century; the Bights of Benin and Biafra contributed significantly to the total, but the greatest number came from Loango and Angola farther down the African coast. Historians have argued that Africans developed new forms of political and social organizations in response to the Atlantic slave trade, but the skills and equipment that made the trans-Atlantic trade possible accelerated the growing technological gap between Africa and Europe. The demand for slaves increased the incidence of slavery in Africa, contributed to the disruption of traditional cultures, and encouraged a callous disregard for human life as people became property. The brutality that accompanied the capture, sale, and ultimately transport across the Atlantic of Africans produced great misery that cannot be mitigated by the remarkable resilience of the people who survived the suffering.