Caucasians did not believe the slaves to be humans, so they treated them like property. Ex. Forcing slaves to eat by branding their mouths, keeping them chained to cramped boards, etc.
It made people handling the slaves harsher. Since there was basically no concern many of them lived in and suffered in inhuman conditions. Eg: Whipped, overworked.
primary sources come directly from the source, so news articles would be good sources. Photos and videos do come directly from the source, as well as documents and speeches.
