In addition, smaller landholders who did not own slaves could rent them from the large slave owners for shorter durations of time, like to get a crop harvested.
Slavery was also central to the Industrial Revolution. It made possible cheap raw materials, mostly cotton, in abundance to run the huge textile mills in England and later other countries.
Tabaco and especially sugar were in huge demand in Europe. Slavery supplied Europe with cheap tobacco and sugar (from central and south America) where slavery was even more rampant than in N America. Later on it was rubber from slaves in Asia and South America.
Slavery was part of a huge globalized economy that could not run without cheap labor. Many people benefitted, not just slave owners. Some people became super rich off of importing cotton (and sugar and tobacco) into Europe and in processing cotton into textiles on a scale previously not possible. Consumers benefitted from less expensive clothing, sugar (which at one time only kings and queens could afford) and tobacco which was becoming a fad similar to our current desire for smart phones made cheaply in Asia. The only way common people could have access to these items was if the labor to produce them was cheap which brought the price way down so mass consumption could make people money.
However, it is also true that only a small percentage of slaves where were transported went to what are today States in the USA. The vast majority went to Central and South America and the Caribbean. They did not fare as well there because of climate and disease, plus they were more routinely worked to death and then replaced with fresh slaves Africa.
There were also many Native slaves in Central and South America ... a practice that happened in the USA in the early years before black slavery ... but soon ended mostly because of disease decimating the number of people available to be made slaves. If the Natives had not died out so quickly it is doubtful so many blacks would have been imported ... but slavery would still have existed. So, history is not kind to Europeans looking back. Natives sold each other into slavery so history, if looked at coldly and pragmatically, is not kind to them either.
Historically speaking, there was a spectrum of conditions between chattel slavery and freedom: serfdom, peonage, indentured servitude, apprenticeship, etc.
Our Declaration of Independence, oddly, probably made the contrast between freedom and slavery more stark. If all men are created equal, yet some men are slaves, then in some way those slaves aren’t “really” men, are they?
There are three logical ways to address this apparent contradiction:
1. Determine that slavery must be abolished.
2. Decide that slaves, and by extension blacks, aren’t really human in the full sense. This is what Taney did in the Dred Scott decision.
3. Decide that the Founders were just plain wrong. All men AREN;T created equal. This is what Calhoun decided and the notion Stephens incorporated into his Cornerstone Speech.