The Atlantic triangular slave trade is for many a dark spot in American history and it has left the country, and others, with some deep wounds that are till this day still healing.
The massive import of slaves from Africa to America increased greatly during the late 1700s and is one of the reasons why the current state of Africa’s countries are far worse compared to European, American and Asian counterparts. Slavery was especially devastating because it decimated the African population, made it vulnerable to colonization, destroyed the chances of modernization and brought political fragmentation. African slavery was terribly negative for Africa because it is responsible for transforming Africa into a dependent continent, which it is till this day.
The first consequence is the displacement of a huge population and growth rate which couldn’t replace the captured slave population. In other words, they sold more slaves than people were born, causing them to lose men. This meant the previous societies were permanently altered and African communities would soon cease to exist.
The second consequence is the development of Islamic slavery. Unlike European slavery, Islamic slavery didn’t stop; rather it prospered because the middle-east didn’t have an industrial revolution like Europe. It's thought that as many people were enslaved in the Eastern slave trade as in the Atlantic slave trade. It's ironic that when the Atlantic slave trade was abolished the Eastern trade expanded, suggesting that for some Africans the abolition of the Atlantic trade didn't lead to freedom, but merely changed their slave destination.
The third consequence is the decline of African trade in the world. Since the slave trade thrashed aside all other forms of trade and development, Africa was dependent on the slave trade. When the Europeans abolished the slave trade in the mid-1800s, poverty rose in Africa because their incomes dried up.