This is actually a really interesting point - European-introduced slavery in the New World was probably the most horrific form of an institution that is already pretty inherently horrific. It started off, well, about as bad as any other form of chattel slavery that accepts high death rates, but escalated through the 17th and 18th centuries to something quite uniquely horrific, finding its final and most vile expression in the racialist ideology of the late 18th to mid 19th century.