It is important to get the record right. Many aspect of slavery in the Americas have been covered up and purposefully ignored. Others have been misconstrued on purpose to serve the political interests of the writer. A short list of what has been largely ignored is as follows.
1. America was not founded ON slavery. It was founded WITH slavery. Slavery existed in the colonies before they were really even colonies. In fact slavery existed on the west coast of America for 270 years prior to the founding of our nation. Think about that number. It was present before America for longer than America has been America.
It was during this period the conditions were harshest. But Africans were not the first. A vital resource in short supply was timber. England, Spain, France, Dutch etc. had done a very poor job of conserving their forests due to the overriding need to create ships. Warships and merchant ships. When the new world was discovered and reports came back of virgin forests as far as the eye could see with huge trees of all kinds the colonial empires set out for the new world. The conditions were harsh and to obtain the labor vitally needed the crowns turned to the judiciaries. If you were an able bodied citizen and found guilty of a crime you were quite likely to end up in the new world as an indentured servant. The standard sentences in England were 7.5 years for minor offenses and 15 for more serious crimes. In many cases charges were trumped up to meet quotas set by the crown.
These weren't African slaves, they were white Europeans. Many were conscripted foreigners rounded up by various means. Prior to this time the Spaniards and virtually every world power in existence throughout the planet practiced slavery. All of China was enslaved, as was most of Manchuria. Australia too was colonized by prisoners.