Slavery existed for centuries before the first slaves came to America. Old Egyptian, Greeks, and Romans owned the slaves. In Africa there were many kingdoms and slavery was legal. When Europeans came to Africa, slavery there already existed.
The first European slave traders were from Portugal. The little country of Portugal built the first European fort in Africa in 1481. It was called Fort Elmina. Soon, people from other countries found out about the slave trade. Spain was one of the biggest slave trading nations. They needed African slaves to work on their plantations in South America and Caribbean. This is where most of the slaves were taken during the first few centuries of the Atlantic slave trade.
England was one of the latest countries to start slave trade. Soon England became on of the biggest slave trading nations. They began to bring slaves to the Caribbean. They formed the Royal African Company in 1672. This allowed English colonies in America to easily buy slaves from English traders. At the beginning only a few slaves came to English colonies. But when the big tobacco and rice plantations grew in the colonies in the south the slave trade increased.
Although many people think that most slaves were stolen or caught by slave traders, this is not the truth. Most slaves were bought by Europeans from other African people. Often, rival tribes sold into slavery members of other tribes they captured during wars. Most of the slaves came from the West Africa and spoke many different languages.