The history of slavery dates back more than ten thousand years. How did slavery first start in Africa?
In the 15th Century, the race to colonize America led European nations to look to West Africa for forced labor. The discriminatory belief that black Africans were less than human enabled traders to view them as nothing more than a commodity and they were treated as such.

For more on the history of slavery and the origins of trans-Atlantic slavery, read on.
Ancient Slavery
The earliest evidence of slavery is the Code of Hammurabi, which was discovered in ancient Mesopotamia, in Western Asia. The text is Babylonian and dates from approximately 1750 BCE. It describes slavery as having already been common in the region for thousands of years.
Sumer is the earliest known civilization in Mesopotamia and is believed to have been the first to use organized slavery. From Sumer, it spread into Greece, where it became part of the culture. This in turn spread to ancient Rome, which was heavily influenced by ancient Greece.
This ancient form of slavery possessed some of the traits of more recent slavery but it was on a far smaller scale. Slaves were often taken in war, as seen when an estimated 50,000 Carthaginians were enslaved by Rome following the Third Punic War.
The lives of slaves in ancient Rome were generally not significantly worse than those of peasants and were sometimes far better. A slave had no legal rights, but the slave of a wealthy owner in Rome could live relatively comfortably.
Trans-Atlantic Slavery
The nature of slavery changed significantly with the fall of the Western Roman Empire. The relatively sudden absence of Roman control around Europe meant that it was possible for other naval powers to rise.
Charlemagne attempted to eradicate slavery in his realm, but the sale of foreigners captured during military campaigns was permitted. This led to frequent enslavement in contested regions.
In countries such as Spain and Portugal, where Christians and Muslims were in regular conflict with each other, women and children were often taken as slaves following military defeats. Though this form of forced labor was based on religion, early slavery was rarely based on race.
The emergence of the trans-Atlantic slave trade in the 15th Century drastically changed this. African slaves, taken by Europeans, were not viewed as people at all, and they were treated as such by their captors.
Queen Isabella of Spain, who had colonies in North America, was asked whether American Indians should be enslaved. As Spain was colonizing the continent, Isabella viewed Natives as Spanish subjects and refused.
Instead, Spain turned to Western Africa as a source of slaves. Portugal had been granted the right to take slaves from Africa by the Pope but Spain was able to negotiate a contract that allowed them access to the coast. England, France, Denmark, and the Netherlands soon joined in the practice.
For many European powers, the thought of using slave labor was viewed as uncivilized and was not permitted within their own borders. That attitude did not extend to their colonial settlements, where they were in a race for supremacy. This was a key reason for the concentration of slaves in North America.
Slade Trade
Trans-Atlantic slavery was the largest forced migration in history, with more than 12 million Africans forced into a life of slavery in the New World. The number of slaves allowed on a ship was determined by weight, which led to about 26% of slaves being children due to their smaller stature.
African slaves were viewed as a commodity and nothing more by their traders. In 1662, Virginia passed a law stating that the status of children was determined by that of their mother.
This resulted in indefinite slavery for generations of people of African descent and allowed the development of both colonial America and the United States as a slave nation. First-generation slaves had known freedom in Africa and some fought to regain it. For children born into slavery, they had never known any other life.
Additionally, it made the slave trade even more profitable; slaves would no longer need to be transported from Africa, so long as slaves in America produced children.
Slave labor was exploited on plantations. The harder slaves were forced to work, the more profit their owners could enjoy. When slaves were worked to death, those profits were used to purchase more slaves, perpetuating a terrible cycle.